MASTER'S THESIS - DiVA portal1025851/FULLTEXT02.pdf · more predictable production time and cost (Gibb & Isack, 2003). Despite this, the implementation has been slow (Goodier & Gibb,

MASTER'S THESIS

Modern Flying Factories in theConstruction Industry

A Description of the Concept and Lessons for Further Development

Sanna HaukkaMagda Lindqvist

2015

Master of Science in Engineering TechnologyArchitecture

Luleå University of TechnologyDepartment of Civil, Environmental and Natural Resources Engineering

i

ABSTRACT

Off-site production is pointed out as a solution to the construction industry’s lack of

efficiency. A way to produce off-site, without a high capital cost, can be found in temporary

factories. It is the basis of a research project, which uses a concept of ‘Modern Flying

Factories’ (MFFs). The concept is today novel and lacks a defined strategic positioning.

However, temporary factories are not something unique and similar concepts can be found

in Swedish field workshops and Flexible Field Factories for the construction industry and

the concept of Mobile Manufacturing for the manufacturing industry. The purpose of this

study is to increase the understanding and facilitate future strategic development by

describing the MFF concept and suggest lessons for further development. The study is based

on a literature review and a case study through interviews and observations of the concept

in its current state with two pilot projects. The ‘Glenfrome project’ was the first pilot project

in which timber and straw bale panels were produced for a school extension. Although the

application of the concept managed to shorten the construction period, the project was

considered to have potential for improved efficiency. The second pilot project, the ‘Battersea

project’, produces utility cupboards to apartments in a major real estate development. This

project was during the time of the study in its start-up phase and several difficulties were

observed. The majority of them could be traced to the design.

This study presents a description of the concept in seven propositions. It proposes that MFF

is an off-site production strategy, which on projects applies a standardized process for start-

up, operation and close down of a temporary factory. Its competiveness against stationary

factories lies in allowing flexibility in location, time and production technique through low

capital investment. The objective is to ensure time and quality as well save costs. The

possibilities for achieving these are however restricted due to not having a continuous

production process. Two alternative strategic directions have been identified for the concept

in the future: continue with low investment costs to maintain flexibility or to automate the

production to increase the efficiency. The lessons in this study are founded in the pilot

projects, as well as what could be learned from theory of similar concepts and

manufacturing improvement methods. Many of the lessons shows a need for an increased

control over the start-up phase and are mainly concerning: decision making, early decisions

and involvement of expertise, increased control over the design and production process and

increased factory friendliness.

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SAMMANFATTNING

Prefabricering pekas ut som en lösning på byggbranschens bristande effektivitet. Ett sätt att

producera off-site, utan en hög kapitalkostnad, kan vara temporära fabriker. Detta är

grunden för ett forskningsprojekt som använder ett koncept med ‘Modern Flying Factories’

(MFFs). Konceptet är idag i sin pilotfas och saknar en definierad strategisk positionering.

Temporära fabriker är dock inte något nytt och liknande koncept kan hittas i svenska

fältverkstäder och Flexible Field Factories för byggnadsindustrin samt konceptet Mobile

Manufacturing för tillverkningsindustrin. Syftet med denna studie är att öka förståelsen och

underlätta framtida strategiska utveckling genom att beskriva MFF konceptet och föreslå

lärdomar för framtida utveckling. Studien bygger på en litteraturstudie och en fallstudie

genom intervjuer och observationer på konceptet i dess nuvarande stadie med två

pilotprojekt. ‘Glenfrome projektet’ var det första pilotprojektet där paneler av limträ och

halm producerades för en skolutbyggnad. Trots att applicering av konceptet lyckades

förkorta byggtiden, ansågs projektet ha potential för ökad effektivitet. Det andra

pilotprojektet, ‘Battersea projektet’, producerar installationsskåp till lägenheter som en del

av en stor fastighetsutveckling. Detta projekt var under tiden för studien i sin uppstartsfas

och flera svårigheter observerades. Majoriteten av dem kunde spåras till projekteringen.

Denna studie presenterar en beskrivning av konceptet som sju propositioner. Det föreslås att

MFF är en off-site produktionsstrategi, vilket på projekt, tillämpar en standardiserad process

för uppstart, drift och nedläggning av en tillfällig fabrik. Dess konkurrenskraft mot

stationära fabriker ligger i att erbjuda flexibilitet i lokalisering, tid och teknik genom låg

investeringskostnad. Målet är att säkerställa tid och kvalitet samt spara kostnader.

Möjligheterna till detta är dock begränsade i och med att produktionsprocessen inte är

kontinuerlig. Två alternativa strategiska riktningar har identifierats för konceptet i

framtiden: att fortsätta med låga investeringskostnader för att bibehålla dess flexibilitet eller

att automatisera produktionen för att öka effektiviteten. Lärdomarna i denna studie grundar

sig i pilotprojekten samt vad som kan läras från teori kring liknande koncept och

förbättringsmetoder inom tillverkningsindustrin. Många av lärdomarna visar ett behov av

en ökad kontroll över uppstartsfasen och berör främst: beslutsfattande, tidiga beslut och

medverkan av expertis, ökad kontroll över utformningen och tillverkningsprocessen samt

ökad fabriksvänlighet.

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FOREWORD AND ACKNOWLEDGEMENT

This thesis is the final part of our studies to get a Master in Architectural Engineering,

conducted for the institution of Civil, Environmental and Natural Resources Engineering at

Luleå University of Technology (LTU). It has given us a valuable opportunity to achieve a

deeper knowledge within construction, which is the area we are passionate about. The

opportunity to study how industrial construction can be applied to a traditional

construction market has been inspiring and instructive. We believe that this meeting will

become increasingly important in the future to achieve a more efficient construction.

The study has been carried out through an Erasmus student exchange, with the University

of Reading, UK, as the hosting university. We are very grateful to have had the opportunity

to live in another country with the inspiring meetings and challenges it has implied. We

would therefore like to thank the University of Reading for giving us this opportunity

despite all the problems that arose along the way.

The first persons we would like to extend a special thanks to are our supervisors. Dr Chris

Harty, for always taking the time for us and giving us essential possibilities for creating this

thesis. Professor Lars Stehn, for your valuable guidance during our work with the thesis.

We also want to express our gratitude to Andrew Skinner for giving us the opportunity to

collect data and for taking time to share your knowledge. Last, but not least, we want to

thank Martin Neeson, Robert McCulloch, Craig White and Jason Loomes for participating in

the study. Without your involvement, this study would not had been possible.

Luleå April 2015

Sanna Haukka and Magda Lindqvist

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EXPLANATION OF TERMS

This study handles several concepts of temporary or mobile production capacity. This section gives a

short explanation of the concepts concerned and gives the abbreviations used further in this study.

Modern Flying A concept for the construction industry with temporary Factory

(MFF) manufacturing in a factory environment. The concept is in a

developing phase and performing pilot projects.

Modern Flying Temporary factories used for production in projects

Factories (MFFs) that applies the MFF concept.

Flying Factory (FF) A concept for production of straw bale panels in temporary

factories. Has been the basis for development of the MFF concept.

Flexible Field A conceptual production concept for the construction

Factory (FFF) industry, which offers mobile and reconfigurable production in

containers with fully automated production processes. Has not

yet been applied in reality.

Mobile Manufacturing A concept for the manufacturing industry, which offers

(MM) mobile and reconfigurable manufacturing in containers with the

possibility to vary the level of automation in the production

process.

Swedish field Temporary factories on the construction site, which started

factories (SWF) to be used during the 60s and function as a workshop. The

temporary factories are simple and could be tents or already

completed buildings at the construction site such as garages.

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TABLE OF CONTENTS

1 INTRODUCTION ........................................................................................................................................ 1 1.1 BACKGROUND ........................................................................................................................................................ 1 1.2 AIM AND RESEARCH QUESTIONS ........................................................................................................................ 2 1.3 SCOPE AND LIMITATIONS .................................................................................................................................... 3

2 METHODOLOGY AND DATA COLLECTION ...................................................................................... 4 2.1 METHODOLOGY ..................................................................................................................................................... 4 2.2 METHODS ............................................................................................................................................................... 6 2.3 ANALYSIS ............................................................................................................................................................ 10 2.4 THE STUDY’S VALIDITY AND RELIABILITY ..................................................................................................... 11

3 THEORY ..................................................................................................................................................... 14 3.1 OFF-SITE PRODUCTION ..................................................................................................................................... 14

3.2 SWEDISH FIELD WORKSHOPS ..................................................................................................................... 23

3.3 MOBILE PRODUCTION STRATEGIES AND AUTOMATION............................................................................... 25 3.4 THE START-UP OF A SYSTEM AND LEARNING BY REPETITION .................................................................... 30 3.5 IMPROVEMENT METHODS WITHIN PRODUCTION ......................................................................................... 33

4 CASE DESCRIPTION ............................................................................................................................... 39 4.1 BACKGROUND OF THE MFF CONCEPT....................................................................................................... 3939 4.2 DEVELOPMENT OF THE MFF CONCEPT WITHIN THE RESEARCH PROJECT............................................... 40 4.3 DESCRIPTION OF THE PILOT PROJECTS .......................................................................................................... 41 4.4 THE CONSORTIUM.............................................................................................................................................. 44

5 RESULTS .................................................................................................................................................... 46 5.1 THE MFF CONCEPT IN TOTAL ......................................................................................................................... 46 5.2 PILOT PROJECT 1: THE GLENFROME PROJECT .............................................................................................. 57 5.3 PILOT PROJECT 2 BATTERSEA: START-UP AND PRODUCTION PROCESS ................................................... 59

6 ANALYSIS .................................................................................................................................................. 70 6.1 MFF AS AN OFF-SITE STRATEGY ..................................................................................................................... 70 6.2 ORGANIZATIONAL PREREQUISITE ................................................................................................................... 85 6.3 DIFFICULTIES IN START-UP AND OPERATION ............................................................................................... 90 6.4 PRINCIPLES FROM MANUFACTURING ............................................................................................................. 91 6.5 CHALLENGES AND BARRIERS IN GENERAL ..................................................................................................... 95 6.6 DECISION BASIS FOR APPLICATION ................................................................................................................. 96

7 CONCLUSIONS ...................................................................................................................................... 100 7.1 PROPOSITIONAL DESCRIPTION ...................................................................................................................... 100 7.2 LESSONS LEARNED .......................................................................................................................................... 102

8 DISCUSSION .......................................................................................................................................... 105 8.1 REFLECTIONS AND RECOMMENDATIONS FROM THE STUDY'S RESULTS ................................................. 105 8.2 REFLECTIONS ON THE STUDY AND ITS PRACTICAL SIGNIFICANCE ........................................................... 106 8.3 REFLECTIONS ON THE STUDY’S METHODOLOGY ......................................................................................... 107

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8.4 SUGGESTIONS FOR FURTHER RESEARCH ...................................................................................................... 108

9 REFERENCES ......................................................................................................................................... 109 9.1 PRINTED SOURCES ........................................................................................................................................... 109 9.2 ELECTRONIC SOURCES .................................................................................................................................... 113

APPENDIX A – G

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1 INTRODUCTION

1.1 Background

For some time, the construction industry has been criticized for its low efficiency.

Reports such as “Rethinking Construction” (Egan, 1998) by Construction Task Force in

the UK and “Skärpning gubbar!”(SOU 2002:115) by Byggkommissionen in Sweden has

highlighted deficiencies such as low profitability, low quality and a lack of radical

change. For improvements in the construction industry, Egan (1998) identified off-site

production through pre-assembly and prefabrication to be of significance.

Over the years, many authors have written about off-site production and its

contribution to the construction industry. The theory, and particularly around

industrialization, has largely been influenced by methods from the manufacturing

industry (e.g. Barlow et al., 2003; Martínez, Jardón, Victores & Balaguer, 2013; Jonsson

& Rudberg, 2014). Design for Manufacturing and Assembly (DFMA) is considered as

an important tool for achieving a cost effective manufacture by evaluating and

simplifying the product structure (Bogue, 2012). Lean philosophy is often seen as one

of the main foundations of industrialised processes in the manufacturing, as well as the

construction industry (e.g. Koskela, Ballard, Howell & Tommelein, 2002; Höök &

Stehn, 2005). Lean production can initiate and achieve continuous improvements in a

process (Alves, Dinis-Carvalho & Souse, 2012) and has pushed the construction

industry towards higher utilization of prefabrication in off-site production (Olsen &

Ralston, 2013).

In literature dating back from 1996 to 2010, the most mentioned drivers for

implementation of off-site production are; more consistent quality and a shorter or

more predictable production time and cost (Gibb & Isack, 2003). Despite this, the

implementation has been slow (Goodier & Gibb, 2007). One of the main reasons seems

to be the high capital cost and the reduced flexibility (Jonsson & Rudberg, 2014).

A solution to this problem might be found in temporary factories. A UK research

project called ‘Near Site, Off Site – affordable near site assembly in

1 Introduction

2

Modern Flying Factories’ has been initiated and implemented by Skanska UK, one of

the country’s leading construction companies. The research project uses temporary

factories, called ‘Modern Flying Factories’ (MFFs) that minimizes required capital

investment, which in turn offers increased flexibility. The concept is, at the time for

writing, in a phase of performing pilot projects and the company is trying to develop a

strategy for implementation in the construction industry. Because of this novelty, the

MFF concept is however poorly explored and lacks a defined strategic positioning.

Currently, there are some concepts similar to the MFF concept. Swedish field

workshops (SWF) are temporary factories on or close to the construction sites,

performed in Sweden during the early 90s and studied by Eriksson (1995). Another,

more recent example of temporary factories for the construction industry is the

conceptual Flexible Field Factory (FFF). The concept is inspired by the manufacturing

industry’s concept of Mobile Manufacturing (MM), which strive for customized

production with automated mobile production capacity (Stillström & Jackson, 2007).

To improve the possibility for the MFF concept to be a way for the construction

industry to become more efficient, research on the concept is needed. Today, the

definition, applicability and potential are not yet studied and such understanding is

fundamental for finding its strategic positioning and for further development. Nor is it

studied how the MFF concept can benefit from experiences of similar concepts (SWF,

FFF, MM) or the application of manufacturing principles (e.g. Lean production,

DFMA). In addition to facilitating in the evaluation of the concept’s strategic

positioning, such studies might also pose valuable opportunities for increasing the

concept’s efficiency.

1.2 Aim and research questions

The purpose of this study is to contribute to increased understanding of the MFF

concept, which can facilitate in assessment of future strategic development. The

increased understanding will also serve as a theoretical basis for further research of the

concept’s definition, applicability and potential. Since the concept misses a conceptual

definition the aim is to propose a theoretical framework that gives a description of the

concept based on propositions as well as suggest lessons for its strategic and

theoretical development. To fulfil the aim, the study will answer the following research

questions:

1 Introduction

3

RQ1: How can the MFF concept be described?

RQ2: What lessons can the MFF concept learn for future implementation?

1.3 Scope and limitations

The study and the data collection have been conducted in a period of five months,

while the MFF concept was in a developing stage and performing pilot projects.

This study is performed on two pilot projects, which so far are the only ones that have

been executed as MFFs within the MFF research project. They have been applied to

buildings in the UK construction industry and so, the study proposes a theoretical

framework for that context. However, the authors have previous experience about the

Swedish construction sector. The study is therefore mainly looking at the concept from

the UK and Swedish construction industry’s perspective.

The description (RQ1) of the MFF concept is concerning characteristics and positioning

in the construction industry. When looking at possibilities for the concept to learn

(RQ2), the study is limited theoretically to look at the concepts SFW, FFF and MM as

well as Lean philosophies and DFMA. The first ones were chosen because of their

similarity to the MFF concept and the second ones were chosen because of their

possibilities for creating improvements in a production process.

The purpose of increased understanding of the MFF concept is not specifically

addressed to a certain actor in an MFF project. Therefore, the study proposes a

theoretical framework of the concept from a broad perspective.

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2 METHODOLOGY AND DATA COLLECTION

2.1 Methodology

In the execution, the research was based on a literature review and a case study on the

concept with its two pilot projects through interviews and observations, see Figure 3.1a.

The pilot projects produced off-site in MFFs for the construction industry. As such,

they offered a good opportunity to explore and evaluate the utility and potential of the

MFF concept in the construction industry. The first pilot project in the case study was

executed and completed in 2012 and consisted of a four-classroom school extension

with prefabricated straw bale panels. The second pilot project was, at the time for

writing, in its start-up phase (since October 2014). It is meant to produce 540 utility

cupboards as a subcontract for the MEP (mechanical, electrical and plumbing) fitting

for apartments. Because of that, the second pilot project provided the opportunity to

study the start-up process and the early stage of on-going production of a MFF, while

the first pilot project provided some results and evaluations from its use.

The University of Reading was also involved in the research project and in that way,

the authors got introduced in the second pilot project. It meant that the authors could

observe the actual production and utilization of the concept. That in turn led to

opportunities to obtain information from interviews and documents. The latter

consisted of a project funding application and an institutional journal article. Data from

these sources dealt largely with the research project and the MFF concept as a whole.

As such, the case study consists of information about the specific projects as well as

details of general character.

2 Methodology and data collection

5

Figure 3.1a The research methodology. A literature review and a case study of the two MFF

pilot projects will contribute to a theoretical framework of the MFF concept

By using a case study approach, the opportunity was given to examine how and why

the MFF concept was applied to the pilot projects (Taylor, Dossick, & Garvin, 2011). As

the concept is novel, these questions were considered fundamental for being able to

describe and learn from the concept. Because of the novelty, the research has had a

qualitative approach. The two pilot projects were chosen to serve as a basis for a

deeper understanding (Yin, 2007). As such, surveys and experiments were not suitable,

as they were considered too limiting to reach that understanding. Instead, the case-

study approach has meant that similarities and patterns that were not expected but

found during data collection could be used to create a nuanced picture of the concept

(Taylor et al., 2011).

As previous research on the MFF concept was limited, the study has had a mainly

inductive (Lancaster, 2005) or exploratory research approach (Taylor et al., 2011).

Instead of having a predetermined theoretical foundation before data collection (e.g.

deductive approach), the theory has been developed simultaneous as the data

collection.

During the early stage of the study, it was focused on trying to explain a general

concept of temporary factories. This was to be done by using the MFF concept as a base

for comparison with the similar concepts of temporary factories (SFW, MM and FFF) to

create a common theoretical framework. However, during the literature review, it

became clear that because of a lack of theory around the similar concepts of temporary

factories, the foundation on which the research would be built on would be too weak.

Also, the findings during observations and interviews supported a study of the MFF

concept on its own better than it would have supported a generalizable theory of

temporary factories. As such, it was instead decided to focus on studying the MFF

concept and use the other concepts for comparisons in common areas and for lessons

to further develop the MFF concept.

LITERATURE REVIEW

CASE STUDY

Documents

Pilot project 1

Interviews

Pilot project 2

Interviews Observations


6

The literature review and the theoretical elements which where studied where altered

and focused to explain the empirical data that has been found. In order to remain

focus, initial research questions served as a guide that the study was directed against.

The preliminary research questions were at the beginning;

1. How can the concept temporary factories be defined?

2. For which projects in the construction industry are the concept of temporary

factories suitable?

3. What can the concept temporary factories learn from the mobile manufacturing

industry?

4. What are the possible difficulties when starting and operating temporary

factories and can lean/5S methods be used for improvement?

The preliminary research questions were revised during and after the late stage of data

collection to suit the findings and ultimately support an in depth study of the MFF

concept instead. This resulted in RQ1 and RQ2, a propositional description and lessons

for future implementation. As such, the inductive approach has helped to guide the

study to more reliable conclusions. It has also supported the study’s aim of increased

understanding of the concept by formulating propositions framing MFF, since the

concept is novel and the theoretical field is poorly explored.

2.2 Methods

2.2.1 Literature review

The research questions required a literature review to effectively utilize existing

knowledge around similar concepts, improvement methods and how learning affects

production. The literature review included both current and older literature on the

subject and was primarily based on peer-reviewed publications. Search was conducted

mostly by Google Scholar, PRIMO (Luleå University of Technology’s E-sources),

SUMMON (University of Reading’s E-sources) and CIS (Construction Information

Service). Examples of keywords that were used separately or combined were; off-site

production, mobile manufacturing, flexible manufacturing, temporary construction,

DFMA, concurrent engineering and lean production.

Theoretical elements that has been considered relevant and how it has been applied on

the different research questions in the analysis is shown by Figure 2.2a.


7

Figure 2.2a Analysis model of how the theory has been applied to the research questions

2.2.2 The case study

The pilot projects have a central role in the development of a theoretical framework for

the MFF concept. They have served as a base in which observations and information

from interviews has been compared against visions and literature. Although the

concept is not fully developed, it has provided a picture of the concept's current state

and helped to evaluate possible strategic directions and development work that the

concept can undertake.

Observations

Observations were carried out at the temporary factory in the second pilot project at six

times by both authors. Two of the visits had durations of a full working day while four

of them were half days. This was done to gather information that helped map the

layout and production process in the factory. The authors got introduced to the project

when it had already been started, approximately 5 weeks into the production process.

It meant that a lot of the observations also focused on mapping the issues to get a

history of the production and understanding of the improvement work.

The observations have been both direct and participating (Yin, 2007). At the first visit,

the authors studied the on-going production objectively to get an initial insight to the

production. During the later visits, the authors participated in the production by

performing quality checks on the cupboards. That meant a greater insight to the design

and process of assembly, which facilitated the understanding of the problems and

improvement work conducted in the factory. As pointed out by Yin (2007),

participation can result in bias as the objectivity may be reduced. However, since the

collected information mostly was of a technical nature, the participation of the authors

was not considered to harm or affect the information substantially. All observations

RQ1. Propositional description

Off-site production

Other temporary and mobile production strategies and automation

RQ2. Lessons leanrned

Off-site production

The start-up of a system and learning by repetition

Improvement methods


8

were complemented through informal interviews with involved people on the sight.

The data collection was performed both during on-going production as well as during

breaks.

Interviews

As the concept is novel, the study was dependent on information through practical

experience of the concept. Therefore, interviews were held with five respondents who

have or have had a position in the pilot projects. This was considered to strengthen

their ability to give an overall picture of the concept. The choices of respondents were

done together with the supervisor, which had insight into the organisations behind the

research and pilot projects. Ultimately, the choices were based on covering different

levels of the organisations as persons with different levels of responsibility contribute

to different perspectives. That was considered to result in as broad picture of the

concept as possible within the study’s time limit. The respondents had the titles of

Managing Director for SRW engineering services at Skanska, Sustainability Manager at

Skanska, Site manager hired by Skanska, Business improvement specialist at Exelin

and Founding Director at White Design Architects. Their involvement in the pilot

projects are illustrated in Table 2.2.1 and relations can be found in Figure 2.2b.


9

Table 2.2 Presentation of the projects and their involvement in the research projects and/or

pilot projects.

Respondent Performed Involvement

Managing Director 19/01/2015

Managing Director at SRW engineering services. Is involved in the strategic development of the

MFF concept. Skanska

Sustainability Manager

30/11/2014

Involved in the development of the MFF concept and got introduced to it during the start-up of the second pilot project. Is both a participant in the

research project and involved in the management of the second pilot project.

Skanska

Site Manager

24/11/2014

Recruited site manager for the off-site factory in the second pilot project. Does not have any direct involvement in the development of the

MFF concept.

Skanska

Lean Consultant

30/11/2014

Business improvement specialist at the manufacturing advisory firm Exelin. Was involved

in the lean improvement work at the first pilot project and has also had indirect involvement in the second pilot project by being participant in

the research project.

Exelin

Design Director

30/11/2014

Founding Director at White Design Architects. Has had indirect involvement in both pilot

projects by being participant in the research project.

White Design

Figure 2.2b The interviewed and their relations to the research project and the pilot projects.

The interviews where semi-structured so that the possibility for responses were open-

ended. That led to valuable information both in terms of facts, but also in terms of the

respondent’s opinion (Yin, 2007). According to Lancaster (2005), group interviews can

MFF RESEARCH PROJECT

PILOT PROJECT 2 PILOT PROJECT 1


10

get fuller information. However, the risk that the respondents would affect each other's

opinions and that only the dominant individuals would get heard was regarded as too

high. The interviews were therefore held individually and face-to-face. They lasted

between half an hour to two hours, depending on respondents' available time and

were conducted at secluded rooms at the university, at the factory site and at Skanska’s

head quarter.

The basis when creating the interview questions were observations from the second

pilot project, theory from the on-going literature review and any previously completed

interviews. The questions where adjusted to the person being interviewed depending

on the background, involvement and position in the development or execution of the

concept, see Appendix C-G. Depending on findings through the other data collection

methods, the interview questions were altered during the process. That was to make

sure that the limited time for interviews were used effectively to answer the research

questions. Nevertheless, they covered either one or both of the pilot projects as well as

the concept as a whole with the main subjects being; purpose, characteristics, execution

and future. The questions were designed to cover facts, experiences and personal

opinions around the concept.

2.3 Analysis

The analysis was done in accordance to Grounded theory, which is based on the

inductive research approach (Lancaster, 2005). The empirical data from the different

data collection methods have been analysed separately and merged to create sections

of the findings in areas found relevant for the concept. Analysis of the results has been

made along the data collection through internal discussions about the findings

between the authors. However, the analysis through processing of the empirical data

into the results was done at the end of the gathering. This was done to get a further

understanding of the concept when performing the analysis.

The analysis started by colour coding the interview transcripts and internal

documents. As such, parts that were considered interesting for answering the research

questions were coloured with the specific question’s colour. Still colour coded, the

parts were thereafter rewritten to a describing text with as much of the respondents

original formulated words left as possible to minimize faults by interpretation. This

was done separately by the two authors and during a review, the parts that were

jointly considered important were taken forward to constitute the findings. Making the

initial analysis separately was done to screen out irrelevant information and reduce the

impact of personal opinions (Lancaster, 2005; Taylor et al., 2011). The findings were

then sorted into topics, which the authors considered suitable. These topics form the

headings of the result section.


11

The analysis of the observations from the second pilot project was made in two stages.

The first one was to identify previous or current problems and challenges in the

production process and the cause and consequence from them. These findings were

then summarized and is presented in the results as a matrix, see Table 5.3, the full

matrix for analysis can be seen in Appendix B. This was being done for the purpose of

classifying the problems and challenges so that improvements could be identified and

suggested as lessons. The analysis was made by both authors in collaboration through

a review of the observation protocols. What was considered a problem or a challenge

for the production was based on what had been expressed by the employees at the

factory or what the authors observed hampered or hindered the production process.

The other stage of analysing the observations intended to identify findings that

described the project and production process, which would help answer the research

questions. As with the transcripts and internal documents, these notes were also found

and selected by the respective author through colour coding and thereafter jointly

reviewing. The findings were then merged with the other findings under the

appropriate existing or under a new heading.

2.4 The study’s validity and reliability

A presentation of validity and reliability as described by Yin (2007) is presented below.

How they have been accounted for in this study by guidelines from the author will

also follow.

Construct validity is treated mainly in the data collection and is about designing real

operational dimensions of the concepts studied (i.e. if investigating what is claimed to

be investigated). It has been considered by the following:

Triangulation has been an important part of the study's construct validity. It

has been ensured through gathering data from multiple sources with different

views/approaches (data triangulation) by different methods (methodology

triangulation) and by two researchers (investigator triangulation). It has helped

to triangulate the data by comparing what has been stated for the concept in

general and what has actually been done in the pilot projects.

Drafts of the different sections of the report have been sent to the supervisors

for review successively during the study to ensure right measures.

The interview question sheets were sent to the supervisor for review before the

interviews to ensure appropriateness and clarity.

A summary of the results from the interviews was sent to each respondent

together with the transcript to ensure correctness.


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Internal validity is the establishment of causal relationship and is treated in the analysis

of data. Yin (2007) states that this kind of validity does not apply to exploratory

research. However, Newman and Benz (1998) do not agree and instead believes that it

is important for every type of research. As such, this study has taken measures to

strengthen the internal validity by:

During the study, alternative explanations have been taken into account as the

empiri has been set against each other whenever possible.

Data has been gathered in a flexible way. Although the analysis of the data was

made in the final stage, the data collection has been based on what the already

collected data has suggested (i.e. theoretical sampling). For example, data from

observations have been part of the basis for the interview questions. In turn, the

interviews have been part of the basis for studying some of the internal

documents. It has been an attempt to capture the best theory to explain the MFF

concept (Newman & Benz, 1998).

In addition, the two researchers have been able to contribute with different

points of view, which reduces the risk of errors from personal opinions.

As there exists no previous studies (as the authors know of) on the MFF

concept, pattern matching has not been an alternative for ensuring internal

validity.

External validity is a delineation of an area within which the study's results can be

generalized (i.e. if the results can be applicable in other settings). In this study, it has

not been a purpose to generalize the results to a wider context e.g. other concepts of

temporary factories. It aims instead to provide a theoretical framework of the concept

in its current stage. This framework can then be used by others as hypothesis for

further studies, which can replicate the findings to develop the theory even further.

However, Yin (2007) emphasizes that even an exploratory approach contributes to a

stronger base for theory building if studying multiple cases. That the MFF concept is

novel and has only been applied to the two pilot projects, has therefore implied a

limitation of the study.

Reliability deals with whether the study’s design can be repeated with the same results.

In this study, it has been accounted for by:

The interviews were recorded and transcribed so that information would not be

lost on the way and for rendition.

Findings of interest during observations were photographed and noted

immediately and summaries of the observations were done afterward in a diary

as an observation protocol.

The data is stored on a file hosting service as well as an external hard drive to

facilitate retrieval respectively to ensure that the data will not get lost.


13

By describing the approach in the study carefully, it is hoped that the study is

replicable for other researchers.

14

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3.1 Off-site production

This chapter review the basis of off-site production and its positioning in the construction

industry. How it is defined and how different techniques are categorized will be outlined. The

drivers and constraints are reviewed to identify the competitive priorities to the use of off-site

production. At last, this chapter also gives an overview of the management and strategy

concerns.

3.1.1 Off-site related terms and categorization of techniques

There are different terms and definitions that are associated or synonymous with off-

site production, e.g.; off-site fabrication/construction/manufacturing, prefabrication,

Modern Methods of Construction (MMC), pre-assembly and standardization (Taylor,

2010).

Prefabrication and off-site fabrication: Jallion and Poon (2008, through Taylor, 2010)

defines prefabrication as a manufacturing process, commonly used in a special plant,

where a variation of materials is brought together to form a component of the final

installation. Further, off-site fabrication is used when both prefabrication and

preassembly are integrated (Gibb, 1999; Jallion & Poon 2008 through Taylor, 2010). The

process of off-site fabrication includes design and manufacturing of units or modules,

often distant from the construction site. Installation for permanent use is being done at

the construction site. Off-site fabrication needs a production strategy that changes the

orientation of the process, from construction to manufacturing and installation. (Gibb,

1999)

Modern Methods of Construction (MMC): The term is used by the UK government to

describe innovations in the construction industry, which aims to make the house

building more efficient. This is done mainly by moving the work from the construction

site to a factory where offsite techniques will be used. (Gibb, 1999)

Standardization: Standardization is in literature frequently found together with off-site

construction (Gibb, 1999; Goodier & Gibb, 2007; Brege, Stehn & Nord,

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2014). Standardization could be defined as “[…] the extensive use of components,

methods or processes in which there is regularity, repetition and a background of

successful practice” (p. 2) (CIRIA through Gibb, 1999). With careful planning, a high

level of standardization and as far as possible in a factory, it is possible to reduce costs

and achieve faster construction time (Gibb, 1999).

Categorization and classification in level of prefabrication are made on recurrent

similar ways in the prior literature (Gibb & Isack, 2003; Goodier & Gibb, 2007; Brege et

al., 2014). A way of classifying off-site construction from a combination of the earlier

literature is shown in Table 3.1.

Table 3.1 Categorization of off-site construction in level of off-site (Gibb & Isack, 2003;

Goodier & Gibb, 2007; Brege et al., 2014)

Category Level of off-site

(increasing) Definition

Component systems

1 Components going into the building.

Example; doors and windows

Non-volumetric units

2 Parts if the building prefabricated in plane

elements. Example; slabs and curtain walls.

Volumetric units 3

Parts of the building are prefabricated in modules. Often finalized internal to 'ready to use' with minimum off-site work. Example;

bathroom pods.

Modular building 4 The whole building is prefabricated in

modules. Often finalized internal as far as possible. Example; housing and prisons.

3.1.2 Drivers

Several articles have studied and in different way, ranked the believed advantages and

drivers to implement off-site production as considered by actors in the construction

industry (Gibb & Isack, 2003; Venables, Barlow and Gann, 2004; Goodier & Gibb,

2007). Time, cost and quality are clearly the words that are in the top of advantages

and drivers (Gibb & Isack, 2003). However, time, cost and quality are terms that can

contain multiple meanings, be divided into subcategories and are often related to each

other. Example of other common perceived benefits are; increased productivity,

minimization of on-site operation, improved health and safety, greater predictability

(Gibb & Isack, 2003), reduced reliance on skilled workers, control in production

process and non weather dependent (Venables et al., 2004). Clients are influential in the

decision-making and therefore, Gibb and Isack (2003) focused on the client’s

perspective on pre-assembly by interviewing clients. They found that the client’s

experience from off-site production where both good and bad. Some had experienced

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direct benefits, while others had experienced bad quality and a poorly functioning

supply chain.

Time was the most frequently mentioned benefit by the clients. Within the time

benefit it was pointed out that pre-assembly leads to less time spent on site i.e.

speed of construction. Other recurrent time benefits were speed of delivery and

less time spent on commissioning. Time is important for clients as the

consequences for not completing on time can mean significant costs. Also, the

risk of a change in the market increases with an extended construction time.

Quality was the second most mentioned category of benefits. A more consistent

quality and better control over the quality were frequently mentioned as well as

minimizing faults and rework.

Cost was the third most mentioned category, with benefits such as reduced total

and overhead costs through less time spent on site as well as less damages and

waste. Cost benefits are important to the clients, especially for repeat-order

clients. It was emphasized as important to look at the total cost instead of

specific building components. When looking at the total cost, benefits such as

decreased preliminary costs, less usage of scaffoldings and get the building

weather proof quickly, should be taken in to consideration.

Although time (first), quality (second), and cost (third) are the three biggest reasons for

clients to choose prefabrication, quality and cost are, at the same time, the second and

third reason not to choose pre-assembly (Gibb & Isack, 2003). This shows that there are

different experiences and opinions about what benefits that can truly be obtained by

using off-site production. Productivity, people and process where other less mentioned

beneficial categories. (Gibb & Isack, 2003).

Although, Neale Price and Sher (1993) argue that prefabrication has clear advantages

on the productivity. A factory environment creates possibilities to apply techniques to

study time and methods, from which productivity can be systematically improved.

The following is a list by Neale et al. (1993) of influences that affect the productivity

through the possibility to produce in a factory:

A better work environment through better lightening, cleaner and safer

working climate.

Better methods, an example is possibility to cast the bathroom floor up and

down in forms, avoiding doing the drainage levels by hand.

Improved accessibility, for example the possibility of erecting walls in a later

stage

Improved accuracy and less time spent on planning due to that the work

becomes more repetitive

Semi-skilled workers can be trained to manage a limited part skilled-tasks

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Solid factory and labour provides good long-term motivations through secured

jobs

Possibility to reduced movement of workers between tasks and breaks

Good knowledge of materials and components used regularly

More efficient sequencing of work by trades operatives

Working methods can more easy be studied to be improved in detail

Less damage caused by other operators / actors

More efficient use of crane, reduced number of lifts

Easier to introduce specialized techniques and tools

3.1.3 Constrains

Several authors emphasized the decision-making for using off-site techniques as

important (e.g. Gibb & Isack, 2003; Goodier & Gibb, 2007). The applicability is

depending on the building type, the client market and the financing (Venables et al.

2004). Neale et al. (1993) mentions project characteristics that are important for decision

making about using off-site production; planned project duration, income generation

of the building in completion, requirements for quality, lack of site working space and

difficulty to access. Neale et al., 1993 argue for the number of possible repetitions as

clearly a factor to take into account to determine if it is able to respond financially

towards traditional construction. The authors also present some project characteristics

that make prefabrication principles not suitable:

In cases where design and production take place at the same time or have

significant overlap in time. This means that the design cannot be freeze, which

makes it more difficult to get the lead-time needed.

Volumetric units can be a problem to integrate in the rest of the building

because of design requirements

The transportation to the construction site should not be underestimated. In

some cases this may make projects unviable.

The reasons when preassembly (manufacture and assembly usually off-site) did not

meet the expectations was mainly because the products where poorly built, that

contractors had a lack of experience or that the design was not correct (Gibbs & Isack,

2003).

A typical manufacturer of off-site has limitations that come with the business strategy.

The typical business strategy is to minimize time variations, have a continuous flow in

the production and aims to be able to plan the production in a long term. This results

in less flexibility and causes difficulties for housing developers or other clients to adapt

the techniques, because of a need for more flexible construction methods. That means

flexible in being able to react quickly to the demands in both speeding up and slowing

down. (Venables et al., 2004)

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Blismas, Pendlebury, Gibb and Pasquire (2005) states that implementation of off-site is

often hindered by procurement constrains. Procurement constrains presented by

Blismas et al. (2005) are when;

project team members lack experience,

key decisions are already made that preclude off-site production,

limited to a particular supply chain,

obligation to accept lowest cost rather then best value and

early construction/manufacturing expertise is not available.

The author's refers to the clients having an important role for creating conditions that

favour instead of hinder off-site production. Pasquire and Connolly (2002) argue that

pre-assembly should be a requirement already in the specification and works best if led

by the client.

3.1.4 Labour skills and innovation

Venables et al. (2004) argue that the UK construction industry have in history had a low

level of education in comparison to other countries and industries. The UK

construction industry has a market with a turnover of labour that makes it hard to

recruit, train and keep labour with the right experience and skills. The author also

argue that an increased use of off-site production can be part of solving the problem of

lacking skills in the industry, especially in housing construction. Also, Goodier and

Gibb (2007) points out that skills shortage has been recognized as a driver for

implementing off-site production. The authors also reported from a survey that 1/3 of

the house builders indicated that it was needed the same or less level of skills by the

labour for off-site techniques. One pole indicated that increased level of off-site

required lower skilled labour and the other pole indicated that it then required a

higher level of skilled labour. Clarke (2002) on the other hand, argues that a skilled and

trained workforce is needed also in the use of off-site production. It is especially

emphasizes that innovation (which is important for example for module making in the

construction industry (Neale et al., 1993)) does not happen without appropriate skills

and training. As such, Clarke (2002) points out the connection between skills shortage,

self-employment and lack of innovations as an explanation to the low productivity of

the construction industry in the UK. It is stated that formal training and skills should

be recognized to improve productivity.

Aside from the level of skill are also different types of skills. Venables et al. (2004)

found that off-site producers do not demand traditionally skilled labour. Instead they

are looking for medium level of craft skills and generally interested in semi skilled or

multi skilled rather than a specifically skilled workforce.

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3.1.5 Changing of roles

An increased usage of off-site production will have impact of the roles in the

construction industry in comparison to the traditional roles. Vokes and Brennan (2013)

argued that the use of off-site production had the most significant impact on higher

level jobs such as; Site supervisors, Designers, Architects, Structural Engineers,

Planners and BIM Modellers. Vokes and Brennan (2013) argue that these new roles

give a need for collaboration and integration between disciplines. It is also argued for a

need for knowledge in; project management, (BIM and automated design tools),

planning and design. The authors predict an increased integration, through skills and

understanding, between design, construction, manufacturing and engineering

disciplines, illustrated in Figure 3.1a.

Figure 3.1a Ideal mix of ‘front-loaded’ skills offsite (Vokes and Brennan, 2013)

Goodier and Gibb (2007) also argue that this early collaborative integration in the

process is important for the possibility to choose the right off-site technique. They also

found that this collaboration need to include the supply chain, which should get more

attention in integration, education and design flexibility.

3.1.6 Decision making and number of repetitions

Since the span of opportunities are wide from non-volumetric applications to fully

finished modular buildings, management actions need to be specific to the project. The

need of the client and available technology must be considered. (Gibb, 1999). Authors

agree that to maximize the benefits of off-site production requires decision timing and

an early decision (Gibb & Isack, 2003; Goodier & Gibb, 2007). The timing is different

depending on projects and techniques and when Pan, Gibb and Dainty (2008) asked

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100 house builders at what stage the off-site techniques where taken into consideration,

71 % answered that they considered it in an early stage (the ’basic house type design

stage’). When the consideration of off-site was made early, it was of volumetric

systems, modular building and some more complex panel systems. Off-site techniques

such as components, subassembly and some open panel systems could often be

considered at a later stage in the process. (Pan et al., 2008)

The study of Goodier and Gibb (2007) indicates that there are doubts, at the same time

as there are believes among contractors, designers and clients, to whether off-site can

be done economical. Several authors agree that there is a problem for decision-making

in the difficulty to prove economical benefits in comparison to traditional way of

building (e.g. Gibb & Isack, 2001, 2003; Goodier & Gibb, 2007; Olsen & Ralston, 2013).

Olsen and Ralston (2013) has found that the decision makers rarely have access to

historical data on costs and times as a basis when making decisions to go with off-site

production.

Evidence of economical benefits is needed in order to facilitate decisions on application

of off-site production. Articles argue that methods should be developed to make

decision makers able to do assessment against traditional built. (Neale et al., 1993;

Goodier & Gibb, 2007). Gibb and Isack (2003) describe cases of re-engineering by pre-

assembly where successes were proven. Further the authors argue that the success is

often in combination with introduced pre-assembly and standardized procedures,

which made it hard to say what really allowed the success. Blismas et al., (2005) states

that common methods of evaluation are often to calculate and compare costs for

material, labour and transportation. This means that benefits from related costs can be

neglected such as site facilities, use of crane and reworks. Also, possible benefits

concerning health and safety, management and process in total are hard to get into

numbers in a economical evaluation. (Blismas et al., 2005).

The suitable scale depends on several factors and it can be complicated to find the right

scale to make benefits. However, Neale et al. (1993) exemplify suitable scales for off-site

techniques like bathrooms or cladding panels. When the construction is fairly simple,

20 repetitions could be a minimum where as 50 would provide better economic

conditions.

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Figure 3.1b The relation between unit cost and repetition (standardization) for precast

concrete cladding (Gibb, 1999)

The graph in Figure 3.1b displays the relation between unit cost and repetition for

precast concrete cladding. It shows a minimum around 10 units to be cost effective and

more repetitions will increase the cost effectiveness. However, it also shows that for

bigger numbers than 30, the unit cost will differ and more repetitions will get less

essential. According to Gibb (1999), this graph looks similar for other off-site

components and manufacturing processes. As such, this graph symbolises the

importance of knowing when to apply the standardized or off-site constructed

components in the projects.

3.1.7 Lead-time and design

Throughout all off-site construction, a longer lead-time represents a significant barrier

in the meeting with the traditional construction (Venables et al., 2004; Goodier & Gibb,

2007). Venables et al. (2004) find a big challenge in the fact that the design processes are

different in time compared to traditional design processes, which states that it is

important to take into consideration. Goodier and Gibb (2007) argue that to overcome

the disadvantages of a longer lead-time, the decision to use off-site needs to be made

early to be able to integrate early in the design process and possibly reduce costs. Höök

and Stehn (2005) also points out the initial design decisions as especially important,

since the longer lead-times that comes with off-site can often mean changes become

more difficult in a later stage. Several articles points out that late changes cause

problems and prevent efficiency in off-site construction. (e.g. Venables et al., 2004;

Höök & Stehn, 2005). Höök and Stehn (2005) argue that late changes can be caused by a

low loyalty to the design of a product, which will reduce the benefits from off-site. It is

important that both clients and employees have knowledge about the consequences of

late decisions.

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Producing in a factory gives other prerequisites than producing traditionally on site.

Pasquire and Connolly (2002) argue that design consultants have a lack of

understanding how to design for manufacture and assembly instead of traditionally.

The authors further state that the designing is not about “carving off a piece of the

work” (p.8) and believe that it can be produced in a factory. Considerations are needed

to be able to realise the benefits that a factory environment implies. In terms of off-site

techniques and approaches to the design, Neale et al. (1993) describe two main

approaches to module design and construction. The first is to have a quite simple

construction technique and an approach that basically moves the work from the

construction site to a factory. Thus using the same traditional material, techniques and

subcontractors as in a traditional built. The second approach is to develop specialized

methods to do specific modules.

3.1.8 Design variation and a strategy for standardization

When offering variation in design, it can be handled in different ways. Venables et al.

(2004) argue that the best way to get economy of off-site techniques in housing is

aiming for a design with possibilities to offer variation with a small variation in the

production line.

There is a balance between standardization and customization that needs to be

considered in choosing strategies. An increased level of industrialization

(standardization) must be weighted against the reduced variety for the costumer.

(Jonson & Rudberg, 2012). Several have studied this balance (e.g. Barlow et al., 2003;

Jonson & Rudberg, 2012; Brege et al., 2014). Barlow et al. (2003) presents a model on

supply chain strategies based on Japan’s off-site housing industry.

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Figure 3.1c Supply chain strategies with examples from the house building industry (Barlow

et al., 2003).

Figure 3.1c shows different supply chain strategies where the extremes are pure

standardization and pure customization. These in turn include different design

strategies and costumer order points. The customer order point or decoupling point is

where the costumer requirements enters and is illustrated by the grey shading. The

model is based on continuous production. The decoupling point can be seen as a

strategic inventory in the supply chain. It is the point that divides the supply chain in

before and after costumer orders. (Hoekstra & Romme, 1992 through Barlow et al.,

2003).

3.2 Swedish field workshops

Off-site production in temporary factories has been performed before. This chapter gives a short

review over the Swedish field workshops, for which concept have similarities with the MFF

concept.

Eriksson (1995) wrote a report about development of Swedish field workshops, with

weather shelter as the main focus. He describes that tents started to be used during the

60s, mainly for concrete constructions. Timber frames began to be used during the 70s

and was until the 80s developed into prefabrication with higher level of completion. It

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also went from lifting blocks by hand to using mobile cranes and tents to secure the

climate. (Eriksson, 1995)

A field workshop can according to Eriksson (1995) be anything from construction on a

worktable to several labours constructing from several steps in the building process.

The author exemplifies various uses for field workshops in wall elements, concrete

slabs, reinforcement stations as well as pipes and electrical work. Further Eriksson

(1995) is studying the production of wall elements in field workshops, some examples

of erected factories performed are; tents, garages (built in a first stage in residential

areas), tents with movable part of the roof to be able to use cranes for lifting and a

more advanced type of tent with slabs with heating coils and walls in blocks (possible

to disassemble). All of them were used with the purpose to secure the climate and to

ease handling, the produced elements where transported on a treadmill.

Eriksson (1995) also studied Skanska’s field workshop in Eklanda, Sweden, for a

development of 1400 two to five story houses of different types, see Figure 3.2. The

construction period lasted about 10 years, starting in 1991. The factory was located in

the middle of the field for the development and measured 13x15 m. It was possible to

customize and be flexible for the production with a tent construction. They created a

wooden floor 0,5-1,2 m above the ground with integrated rails.

Figure 3.2 Photos and layout of the field workshop in Eklanda (Eriksson, 1995)

The idea was to “[…] create an effective and cost conciseness work environment which

emphasizes a good working environment.” (translated) (p. 2). The project was to

develop systems for light weighted and appropriate field factories while combining

good working environment with good economy. Also quality improvements were

considered as benefits from being able to weather and moisture proof the wooden

construction. (Eriksson, 1995)

Fundamental thoughts and goals with the project in bullet points are (Eriksson, 1995):

Create a good working environment from an ergonomic point of view.

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The field workshop was planned to be independent from a stationary crane or

loader. Loaner was only supposed to be used for transportation for assembly

with the finished elements.

The design of the factory was supposed to be given a high flexibility for a

varied use during a long time.

The factory should be executed on existing ground without expensive

groundwork.

The factory would be built up of hired equipment to enable fast closedown and

later on a fast start-up.

3.3 Mobile production strategies and automation

A more up-to-date version of temporary factory production as opposed to SFW, is today's

mobile production strategies with automated production processes. In the manufacturing

industry, the concept of Mobile manufacturing is an example, while the Flexible Field Factory is

a similar concept adapted for the construction industry. This chapter provides an overview of

these concepts accompanied by a brief review of some bases for implementation of automation.

3.3.1 Mobile manufacturing

Demands on the manufacturing industry

The literature on manufacturing presents a necessity to re-evaluate current production

strategies (e.g. Mehrabi, Ulsoy, & Koren, 2000; Stillström & Jackson, 2007). To be

competitive, Jackson and Zaman (2007) says that it is no longer enough to simply

produce with low cost and high quality. Companies are also encouraged to create more

flexible (Ask & Stillström, 2006; Manufuture, 2004) and unique production capabilities

(Jackson & Zaman, 2007), which can quickly adapt to the changing environment

(Stillström & Jackson, 2007). Mehrabi et al. (2000) provide a more concise guidance

when they state that manufacturing companies must create production systems that

can be easily upgraded, in which new technologies and new functions can be easily

integrated. The authors believe that this requires a strategy that enables:

Rapid conversion - for the manufacture and sales of new product models

- of manufacturing systems capacity to market demand

Fast integration of new technologies and new features in existing systems

Simple adjustment of varying amounts of products for niche marketing

As a summary, ManuFuture (2004) notes that investing in large monolithic mass

production plants just seeking to make profit from economies of scale no longer makes

any sense.

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The concept of Mobile Manufacturing

The concept of Mobile Manufacturing (MM) has mobility, flexibility and speed as its

competitive goals (Ask & Stillström, 2006; Stillström & Jackson, 2007). Stillström and

Jackson (2007) define mobility as ”the ability to change between geographically

different places with little penalty in time, effort, cost, or performance.” (p. 189) The

concept of MM is based on the idea that mobile manufacturing modules provide

mobile and flexible production capacity for customized manufacturing. By combining

the modules, it creates a complete manufacturing system that in size and production

capacity can be adapted to suit the need of different customers. The modules have a

reconfigurable manufacturing system, which can be quickly and rationally replaced

and rearranged to handle new products and/or new volumes. (Stillström & Jackson,

2007)

Ask and Stillström (2006) claim that the responsiveness of production systems will

increase with MM, both in the production process and geographically, making all sizes

of companies more competitive on the global market. The geographic responsiveness

in which production capacity can be close to the need or the skills, is by Stillström and

Jackson (2007) emphasized as increasingly important for companies in the future.

Jackson and Zaman (2007) have determined that implementation of MM will enable

and support methods for increasing flexibility, mobility and speed, such as:

Increasing the level of automation in manufacturing processes

Working with standardized part families by increasing the modularity in

products

Having prefabrication of sub-systems close to final assembly

Creating close collaboration with sub-contractors and -suppliers

Developing and improving logistics

When implementing a MM system, it is important with a business model that supports

the change as well as efficient knowledge and information handling system. This

means that staff that will manage and perform production must be well trained. This is

due to that the concept will imply new challenges on a company’s organization,

technology, company strategy, knowledge feedback and information flow. Also, the

existing main hard- and software has to be configured for the new requirement and

existing methods and systems that support the change has to be identified. (Ask &

Stillström, 2006)

Factory-in-a-Box: Demonstrators of the concept

To demonstrate the concept of MM, five demonstrators have been produced in a

project called ‘Factory-in-a-Box’. The project was collaboration between several

manufacturing companies in Sweden and four Swedish universities. (Stillström &

Jackson, 2007) The aim of the project was to provide solutions for mobile and flexible

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production capacity on demand (Ask & Stillström, 2006; Jackson & Zaman, 2007). In

the project, the manufacturing modules consisted of standardized containers that

enabled easy and quick transportation to and/or within a manufacturing site, with

truck, train or boat etc. (Jackson & Zaman, 2007). They were built for various types of

classical manufacturing such as assembly of components or casting of goods. The

modules had varying levels of automation, from completely manual to fully automated

and the systems were reconfigurable with movable robots and equipment (Jackson &

Zaman, 2007; Stillström & Jackson, 2007). One of the demonstrators where made in

order to be transported easily between countries (Jackson & Zaman, 2007). This was

facilitated by having a technical solution with a collapsible container, see Figure 3.3a

(Stillström & Jackson, 2007).

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With this type of production solution, the company was given the opportunity to offer

their own production instead of outsourcing it (Stillström & Jackson, 2007).

3.3.2 Flexible field factories in the construction industry

A research project that has many similarities with the MM concept is ‘Flexible Field

Factory’ (FFF). Research on the concept has been conducted by Martínez et al. (2013)

and involved a conceptual mobile production strategy for the construction industry.

The goal with the study was to create a building-manufacturing paradigm for an open

system of products and components through manufacture in factories and on-site. The

study also aimed at combining design with highly efficient industrialised production

by integrating robotics, ICT systems and new material and technologies amongst

others, to the concept.

Within the study, a mobile, semi-automated and reconfigurable factory prototype was

simulated for on-site prefabrication of installation modules into an apartment building.

The factory housed in a standard container with integrated legs that allows easy

transport and unloading by truck, see Figure 3.3b (Martínez el al., 2013).

Figure 3.3a The technical solution of one of the demonstrators as a combined collapsible

container (Stillström & Jackson, 2007)

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The work on FFF began with an analysis of the manual production of installation

modules. Thereafter, lean and DFMA principles were used for dealing with limitations

identified and create an efficient and flexible automation of production. With DFMA,

the installation modules were redesigned to better suit an automated production

concept. (Martínez et al., 2013)

According to Martínez et al. (2013), the production would achieve a high flexibility

through a multipurpose robot that had the ability to have tools or parts replaced to

perform different tasks. The robot also had reconfigurable software that enabled

changes in the sequence of the workflow or collaboration with other machines.

3.3.3 Automation – The future of production?

The concepts described above strongly advocates an increased automation. However,

there are different opinions whether automation is believed to be beneficial for a

production system. Through previous research, Mehrabi et al. (2000) have found that

there are two ways to see the balance between human and machine. In the first, the

human is seen as a source of error and automation is believed to be necessary to create

stable and secure systems. The other view believes that humans are needed to correct

errors, but also that humans in general are always needed and that our ability of multi-

skilling is important. As an example on the first point of view, Martinez et al. (2008)

claim that automation reduces dependence on direct human labour, which has a

positive impact on quality and labour costs. Furthermore, the authors argue that

automation also increases the productivity, safety and competitiveness. The last one is

a result of reduced costs as well as increased control over the production process and

product due to increased inspections. Martínez et al. (2013) have extended that view as

they claim that the final quality of the product in a manual system may vary as it

Figure 3.3b Transportation and unloading of the Flexible Field Factory (Martínez et al.,

2013)

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depends on the skill of the worker.

From the research performed by Ask and Stillström (2006) and Stillström and Jackson

(2007), it may be noted that not all companies benefit from a high level of automation.

This is for example the case when lot sizes and number of variants makes it too

complex and expensive to automate the process (Stillström & Jackson, 2007).

3.4 The start-up of a system and learning by repetition

When having production in temporary factories, the projects will always face start-ups.

Therefore, this chapter gives a brief overview of the theory of learning curves and how it

displays the effectiveness of a company's start-up phase. It also provides a picture of the

difficulties a company face when starting a new production process.

3.4.1 Learning curve theory

When a job is repeated, the time of completion will decrease with increasing repetition

frequency according to a certain pattern. This phenomenon is called the learning curve

or experience curve since it also treats the rate of experience. (Reis, 1991; Huang &

Man, 2010) The learning curve can be divided into two phases where the first, phase A

(see Figure 3.4), represents the start-up phase, in which the learning increases rapidly

with increasing repetition. This contributes to a reduction in production time per unit,

i.e. completion period. Phase B reflects the steady state, where the learning process has

decreased to almost non-existent and completion time is relatively stable. (Baloff, 1970;

Ghemawat, 1985; Huang & Man, 2010) According to the theory of learning curves, the

rate of learning will be 80 % with doubled quantities, which means a 20 % decrease of

production cost each doubled output (Hirshmann, 1964; Argote & Epple, 1990).

Ghemawat (1985) argues however that when considering benefits from learning in

planning, the learning must not be overestimated because the schedule can then

become too tight. The ability to learn has been shown to vary depending on how well

the company encourages cost cutting and the type of product or service the company

offers (Ghemawat, 1985).

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Learning is important for productivity and performance improvements in a start-up of

a production process. If disruptions occur during the start-up, it might pose major

problems for a company. This is because it can lead to large deviations from the

theoretical learning curve. Depending on the severity of the disruption, the system can

either recover or be permanently damaged. The last case is represented by a raising of

the continued learning curve’s position. Consequently, when a disruption or

discontinuity of the learning happens, a relearning have to occur. (Baloff, 1970) This is

what can happen when introducing a new production system (Almgren, 1999) or

making a significant change to an already existing one (Baloff, 1970). Employee

turnover is also a sort of disruption and if the staffs are the ones that possess

knowledge within the company, an employee turnover can mean that large parts of the

organizational knowledge disappear. A solution is to standardize tasks. This means

that the company is no longer as sensitive to a turnover, since the knowledge is not

possessed by the specific workforce. (Argote & Epple, 1990)

3.4.2 The start-up of a system

In the start-up of a new system, the result is often not what was expected and planned

for (Baloff, 1970). Harrison (1981) describes that by the following:

“Equipment does not operate properly, roles and responsibilities are unclear or

disputed, tasks are not carried out as expected, human and material resources are not

available when needed or do not perform as expected, and so on.” (p.6)

Figure 3.4 The learning curve – In the start-up phase (phase A) the learning increases rapidly

with increasing repetition, while the steady state (phase B) represents the stable phase

where learning is stagnating (Hirschmann, 1964, remade with theory from Baloff,

1970)

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The start-up phase often means a great stress for those involved in the process,

resulting in that problems, which normally seem small in a steady state, can be large

and involve disruptions in the start-up (Baloff, 1970). Harrison (1981) points out the

importance of understanding that a company in its start-up phase has different

requirements than a company in its steady state. The author shows the difference when

he exemplifies that a company in its steady state should be seen as a producing system

while in their start-up phase, the company should instead be seen as a learning system.

When errors occur, a learning system interprets it as a way to learn rather than a

failure, allowing for more rapid improvement of the process.

Baloff (1970) has in a study of several industrial companies in the start-up phase,

concluded that the major errors committed in this stage can be divided into four main

categories; changes in product design and production factors, discontinuous

manufacturing policies, commission of technical supervision and assistance or

ineffective motivation and compensation programs.

Changes and discontinuity in production

The start-up of a new process can be significantly affected by changes in product

design, product mix or production factors such as labour, materials, supplies, tools, etc.

(Baloff, 1970). Baloff (1970) argues that design modifications that create changes in

production factors are an especially big risk as it can create a slower rate of learning

throughout the whole lifecycle of a production process. To reduce the risk of such

disruptions, Almgren (2000) notes that it is a good idea to spend extra energy on

ensuring the proper functions of all of these areas before starting production. It is also

important to plan for a smooth and levelled production and predetermine measures

for future potential problems (Baloff, 1970; Almgren, 2000). In order to avoid sub-

optimization in the planning of error handling, the entire project team of designers,

suppliers, senior production staff and equipment operators should participate and the

responsibility of each partner should also be investigated (Harrison, 1981).

Technical supervision

Harrison (1981) argues that start-up companies should take help from a start-up group

that has the operational and technical skills to assist in the production process. The

author exemplifies that in addition to helping the workers in learning their tasks more

efficiently, this can also ease in the information handling for senior staff.

Baloff (1970) and Almgren (1999) have also concluded that automated systems could

increase their efficiency by incorporating technical expertise in support of learning.

Baloff (1970) argues as an example, that his experience has shown that production

systems with automation or more advanced technical systems often have a higher

sensitivity to disorders. This is because of the many interdependent operating variables

that have to be handled.

Motivating the workforce

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The workers are a critical source of an efficient start-up. It is therefore important to

encourage them to cooperate in improving the process (Baloff, 1970). Furthermore,

Harrison (1981) and Reis (1991) adds that it is important to involve the workers early in

the process. To allow them to participate in the planning of tasks reduces the risk of

surprises and ineffective work due to lack of structure, which can shorten the start-up

phase significantly.

3.5 Improvement methods within production

To strive for improvement is important for all production, not least for factory production. In

this chapter, the improvement philosophies Lean production and Design for Manufacturing and

Assembly (DFMA) will be presented. They are both methods that have their origin in the

manufacturing industry and have later been adapted to other industries such as for off-site

production. As the MFF concept acts in the construction industry, this chapter will also give a

brief overview about how the lean philosophy has been adapted to fit it.

3.5.1 Lean production

The concept of Lean production

The definition of ’lean’ is quite diffuse, which is reflected in the many definitions and

interpretations of the term that can be found in the literature. However, regardless of

the interpretation, Sangwan and Bhamu (2014) points out that there are essentially two

main views for how to use ’lean’; either as a philosophical guidance toward principles

and objectives or as a performance guide consisting of techniques and tools. In Lean

production, great emphasis is placed on eliminating waste by creating a system that

requires minimal resources in the form of materials, parts, tools and workers

(Sugimori, Kusunoki, Cho & Uchikawa, 1977).

Methods of lean production

In a summary of the literature on Lean production from the years 1984-2004, Pettersen

(2009) has found three characteristics of lean production. These are; setup time

reduction, continuous improvements and just-in-time production. How they relate to

each other and contribute to the goal of Lean production are explained with ’The

House of Lean Production’, see Figure 3.5.

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Figure 3.5 ‘The House of Lean Production’, which symbolizes the goal of Lean production

and how different parts of the philosophy contributes to achieving it (Dennis,

2007)

The foundation: Stability and standardization

5S is a method that can be used to create stability and standardization in a process

(Jaca, Viles, Paipa-Galeano, Santos & Mateo, 2014). Just as Figure 3.5 shows, the method

is a natural first step in an implementation of lean philosophies and practices as it

supports Just-In-Time and continuous improvements (Dennis, 2007; Gapp, Fisher &

Kobayashi, 2008). 5S stands for Organization, Orderliness, Cleanliness, Standardized

clean-up and Discipline. The responsibility for creating and maintaining discipline lies

with the management. Managers must set a good example and constantly strive to

anchor the values to the entire plant. (Hirano, 1995)

Continuous improvements or Kaizen is also an important part of standardization.

Dennis (2007) emphasizes that without improvements, a system will regress. The

PDCA (Plan-Do-Check-Act) cycle is a method that can help incorporation of

continuous improvements in a business. The tool is used to minimize the gap between

customer need and process performance, which will lead to high customer satisfaction.

(Gitlow, 1989)

The first pillar: Just-in-time

Just-in-time production (JIT) as a concept has its foundation in that stock is seen as

waste (Sugimori et al., 1977). For JIT to work optimally, it also requires a continuous

flow that pulls material from an upstream to a downstream station across the whole

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process (Dennis, 2007). A method that supports this is Kanban, which is a way to

reduce the lead-time in manufacturing (Sugimori et al., 1977). The pull system is

supported by the factory's takt time or paced production, which describes the rate of

which parts are assembled in the factory. To create a smooth flow and setting a pace

(rather then chasing a demand), the takt time has to correspond to the flow at which

the finished products go out of the factory. (Hopp & Spearman, 2004)

The second pillar: Jidoka

Lean production is a system that demands that personnel do not pass on defective or

overproduced parts (Sugimori et al., 1977). If a defect part is forwarded, it will be

noticed in the next station, which means that production must be stopped. This

approach is called Jidoka and is an important part for ensuring a continuous flow.

(Dennis, 2007)

The interior: Involvement

Alves et al. (2012) explains that Lean production challenges the workers to improve

processes and operations. This is done by giving them freedom to control their own

work under responsibility and by motivating teamwork. Dennis (2007) emphasizes

that the involvement of team members is a critical part for the ability of making

continuous improvements.

Limitations of Lean production

Although many praise Lean production as a tool for increasing efficiency, there are

also some limitations of the concept. A study performed by Eroglu & Hofer (2011)

investigates the effect of inventory leanness on firm performance within different

industries. The results of the study show the following trends:

Large companies (many employees and companies with high gross margins)

achieved greater effect of inventory leanness on firm performance than small

firms

Some industries are more appropriate for Lean production philosophies than

other, depending on type of product, production technology and supply- or

demand characteristics.

The effect of inventory leanness on firm performance follows a U-shaped curve,

i.e. there is an inflection point where investments are more costly than the gains

made.

As a summary, the results suggest that increased efficiency can be obtained from

implementation of Lean production philosophies depending on various factors of the

individual company (Eroglu & Hofer, 2011).

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Lean philosophies in the construction industry

Unlike the repetitive and relatively stable state in the manufacturing industry, the

traditional construction industry is more uncertain. This is due to its properties as on-

site, one-of-a-kind and complex production. In order to suit the construction industry,

Lean production has therefore needed to be adjusted, resulting in the concept of Lean

construction. Lean construction extends beyond the traditional design-build

contracting, which Koskela et al. (2002) believe solely focuses on the transformation of

the product and therefore misses the point of increasing the value and creation of flow

in the process. To achieve this, it is important that all project participants collaborate in

the project's early stages.

Lean design has an important role in Lean construction and is about the project team

together seeking opportunities in design that can increase the overall value. It aims to

reduce early design freezes. This could otherwise lead to rework when there has not

been time to investigate the influence of different disciplines thoroughly. The method

is based on that decisions that affect the design are taken in the last responsible moment.

This is to be done with a basis by backwards planning, which is a function of lead time,

as in turn benefits from reduced lead times within the supply chain. (Koskela et al.,

2002)

However, in a study of integration of Lean construction, Pasquire and Connolly (2002)

highlight some difficulties to achieve a lean project delivery in the construction

industry. The authors recognizes the importance of a properly performed design and

further, the authors criticize construction project management for generally having an

approach that expects flaws and errors. The management is more about a ‘fire fighting’

approach rather than preventing problems in advance and it is hard to convince

participants to work for mistake proofing. According to the authors, it is often blamed

on the construction industry having a fragmented nature, which counteracts early

communication and early joint discussions on project objectives. The traditional way

with a ‘fire fighting’ approach relies on buffers by building in ‘fat’, which is the

opposite of a lean philosophy. Significant changes across the industry are needed to

begin to overcome these problems and be able to integrate Lean construction. (Pasquire

& Connolly, 2002)

3.5.2 Design for manufacturing and assembly (DFMA)

Most traditional manufacturing design processes will encounter problems when the

product design is passed on from the designer to the manufacturing and assembly

engineer (Boothroyd, 1994; Bogue, 2012). Bogue (2012) explains that few designers

have the knowledge of different techniques and materials to optimize a design by

themselves and therefore tend to stick to design options they are familiar with.

Boothroyd (1994) argues that early teamwork between the disciplines together with the

specific analysis tools that DFMA can offer is a way of meeting this problem.

Bogue (2012) states that it is known that around 70 % of a product’s manufacturing cost

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is derived from decisions made in the design stage. Also, Boothroyd (1994) explains

that the further in the design process changes occur, the more expensive the

production cost. Because of that, the author emphasizes the importance of taking

manufacturability into account as early as possible in the product development. Both

Boothroyd (1994) and Bogue (2012) argue that the extra time spent early in the process

will be more than compensated for later in the production state.

DFMA philosophy

DFMA philosophy is divided into two stages. The first is represented by the Design for

Assembly (DFA), where the design of the product is evaluated to maximise the use of

components (Edwards, 2002) for reduction in assembly and total parts costs

(Boothroyd, 1994). Boothroyd (1994) explains it as an iterative process to simplify the

product structure by minimizing the number of parts but still satisfy the constraints of

the product design. When that is done and still in the DFA stage, different material and

processes will be evaluated and cost-estimated for the various parts. Because most of

the manufacturing information about the different design options can be transformed

to costs, the method will allow for direct comparisons (Edwards, 2002). The most

optimized design concept will then be taken to the Design for Manufacturing (DFM)

stage (Boothroyd, 1994). At this point, the product will be in detail designed in search

for the minimum manufacturing cost (Edwards, 2002).

When simplifying the product, Boothroyd (1994) states that there will be a snowball

effect on the reduction of costs. That is because when parts are reduced it will also

reduce the number and handling of drawings and specifications as well as vendors and

inventory. Also, the strive for simplicity will, besides minimizing the production costs,

shorten the lead time for production development and manufacturing, making the

product reach the market more quickly (Boothroyd, 1994). When the production is

characterized by low labour costs but instead also low technical skills, using DFMA

principles will be even more important. The author points out that this is often the case

when outsourcing production and ensuring an effective assembly is therefore vital to

ensure delivery time with a high quality and low costs. (Bogue, 2012)

In cases were the assembly process is automated, Boothroyd (1994) states that

implementation of DFMA philosophy will often mean redesigning the product.

However, the author also states that when redesigns have been made for automated

assembly, the final product has end up so simple that automation could no longer be

motivated. Be the assembly process automated or manual, Edwards (2002) points out

that an efficient assembly is together with efficient component manufacturing

however, the most important aspects of the DFMA philosophy.

As for the product type applicable for DFMA principles, it can span from short-lived

mass-produced products to long-life more unique ones (Edwards, 2002). Boothroyd

(1994) claims that there is a perception that DFMA is only applicable to products in

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large volumes. The author claims that it is just the opposite; when producing with low-

volume, the initial design is usually not reconsidered and doing it right the first time is

therefore even more important.

Methods for implementation

There are three ways of implementing DFMA philosophies to a product development

process. The first is to use DFMA guidelines. The second is to use a DFMA score

system in which each part of the product design is evaluated and scored depending on

its ability for smooth assembly. The third consists of automating the entire product

developing process with software tools. (Bogue, 2012)

39

4 CASE DESCRIPTION

In this chapter, the MFF research project as well as the two pilot projects will be presented. The

information is primarily based on received documentation, which consisted of the project

funding application and an institutional journal article.

4.1 Background of the MFF concept

‘Near Site, Off Site – affordable near site assembly in Modern Flying Factories’ is a

research project founded by Skanska, with the purpose to develop and trial the concept

‘Modern Flying Factory’ (MFF) (Skanska, 2012). The MFF concept has its origin from a

concept called ’Flying Factory’ (FF), which ModCell, a UK building company using

straw and timber elements, is the founder of, see Figure 4.1. Skanska had been

interested in prefabrication for some time and were after collaboration with ModCell,

fascinated by the concept’s benefits. However, they saw the concept to be too limited

and wanted to show that it has a lot more potential by bringing in efficiencies from

other industries and applying it to projects with other components than straw bale

panels. (CIOB, 2013)

The concept of FF is, according to the Design Director, conceived to be “[…] the least

amount of money we could invest, but still do prefabrication”. ModCell therefore hires

farmer barns, which are light industrial sheds, as temporary factories. The Design

Director says, “The Flying Factory only exists to deliver the project”. Except

minimizing capital cost, it is also fundamental for the concept to keep the production

process as simple as possible. To achieve that, they have adapted principles from

DFMA and Lean production. This has resulted in a standardized process where the

only equipment used are drills, hedge trimmers and leaf blowers. The Design Director

means that as a result, anybody can work in the production of the straw bale panels

because ”it is easier to make than an Ikea cupboard”. As such, they are striving to

industrialize the delivery of sustainable construction by using simple materials, simple

methodologies and no investment. ModCell has however been looking

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at the possibility to implement a movable container with a full automation to their

production, which is thought to reduce labour time. The criteria for implementation

are that the equipment needs to fit in the container and is has to be able to be driven to

the site as well as take no more then one day to set-up or dismantle. This will however

not be implemented until they have a continuous demand for it.

Figure 4.1 The development of the MFF concept from the concept of ’Flying Factories’ with

founders and possible production techniques

The MFF research project has earned £0.75 millions in grant from the Technology

Strategy Board (TSB), UK’s innovation agency, for the purpose of trying out new

approaches to reduce time and waste (CIOB, 2013). Besides the two pilot projects, the

concept is to be applied on two to four more projects within the research project.

(Skanska, 2012)

4.2 Development of the MFF concept within the research project

The intention with the research project is to develop the MFF concept by building to

the FF concept. The use of the ModCell’s FF approach for the project was thought to

provide a suitable test case for research and development work. This is because it uses

a non-traditional supply chain and is a novel construction process allowing greater

freedom to innovate. (Skanska, 2012) The MFF concept will be developed by

integrating best practice logistics and supply chain management techniques from the

utilization of among other, ICT (Information Communications Technology), RFID

(Radio Frequency Identification) and Lean philosophy.

In the research funding application it was stated that ICT would in this case consist of

novel uses of BIM or augmented reality by using 3D projection. It is believed to help

guide the construction team both on and off-site and may make it easier to involve

innovative suppliers. Lean principles will be applied to achieve waste reduction, which

is considered to involve programme and defect reductions, reduction in supply chain

costs, management time, material waste, changes and resources to manage changes.

Modern Flying Factories

Flying Factories

Skanska

ModCell

Straw and timber elements

Different production techniques

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41

The objective with implementing RFID tracking to the concept is to facilitate materials

tracking to ease site logistics. (Skanska, 2012)

As the MFF concept is thought to handle different techniques, it is stated that pilot

projects within the resarch project will handle different materials and construction

types. (Skanska, 2012)

4.3 Description of the pilot projects

General information about the two pilot projects can be found in Table 4.3 and it shows

the differences in both the scale and type of project.

Table 4.3 Information about the two MFF pilot projects, which displays the differences in

type of project, scale and duration

Glenfrome Battersea

MFF part of project Straw bale panels Utility cupboards

MFF contract type Main contract Subcontract

Contract sum £1.7m £89m

Construction period During summer holiday 2012 2014-2016

4.3.1 The Glenfrome project

The ‘Glenfrome project’ was the first pilot project and consisted of a four-classroom

school extension and a little library at Glenfrome Primary School in Bristol. Skanska

had the main contract for this project and the responsibility for constructing the

foundation and completions. ModCell offered the frame of the building, a total of 18

straw and laminated timber panels, see Figure 4.3a. They were constructed in a

temporary factory contained in a farmers building 13 km from the construction site.

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Figure 4.3a A ModCell panel being assembled in a farmers' barn for the Glenfrome project

(Courtesy of Construction Research & Innovation, Vol. 4 Issue 1 March

2013)

4.3.2 The Battersea project

In the ‘Battersea project’ is the second pilot project. Skanska has developed a

temporary factory that will prefabricate 540 utility cupboards. They will be fitted in

two new apartment buildings in a major real estate development in Battersea, London,

called Circus West. The development is a mix of residential and commerce, consisting

of seven main phases as a redevelopment. The two apartment buildings in Circus West

is the first phase of the Battersea development. They will be 15 and 17 stories high,

include 866 apartments and have an estimated cost of £90m. (Construction News, 2014)

The production of the utility cupboards is part of a bigger subcontract that Skanska

have for MEP services. The reason for not prefabricating utility cupboards for all of the

866 apartments is due to the complexity of some apartments floor plans. The remaining

326 utility cupboards will as such be built on site. For the second phase, Skanska will

be the main contractor, in which the MFF cupboard concept will be applied again.

Skanska hires an industrial unit in a trading estate in Slough, 40 km from the Battersea

project, in which they have set up the temporary factory for the utility cupboards. In an

adjacent unit, Skanska has a stationary factory for off-site MEP-components. This

stationary factory is separated from the Battersea project producing cupboards

although they have some exchange between each other such as lending of factory

space and employees.

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Figure 4.3b The temporary factory in Slough where the cupboards are produced. The

production process had in the beginning doubled numbers of units in working

progress due to disruptions, which hampered the production flow

Figure 4.3c The factory floor in a more stable state with less work in progress

The cupboards have different measures although the main part of them measures

about 0.6x1.7x2.4 m. All of them contain MEP services for the apartments such as; tele

communication, media, electrical distribution, washing machine (installed on site)

ventilation and heating units. The structure of the cupboards is a painted steel frame

covered with plywood and plasterboard. Nearly all MEP components are fitted before

the modules leave the factory. The transportations of the cupboards are coordinated

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44

with the transportations of bathroom pods from Germany and will be lifted in place

and installed in a similar way. Doors to the cupboards will be fitted in a later stage on

site. The original plan was to have 20 units in working process and 20 finished units

stored between deliveries at all times. It was planned for storage in an adjacent

building rented for this purpose. The factory has struggled in the start-up phase due to

a variety of reasons. Figure 4.3b shows the factory in a phase where the first cupboards

have not yet ben shipped out. It was then about 40 cupboards in production instead of

the planned 20. In Figure 4.3c, the production process had got relatively stable with a

decreased number of units.

4.4 The consortium

Below is a list that presents the participants in the research project and their

involvement in the projects. This is also visualized in Figure 4.4.

Skanska UK A multi-disciplined construction company offering design,

construction and facilities management services. They are leading the

research project by engaging supply chain partners in the pilot projects

and are together with the rest of the consortium developing the

concept from gained experience.

ModCell A company that develops prefabricated straw bale construction

systems for amongst others housing, schools and other commercial

buildings using Flying Factories. In the Glenfrome project, ModCell

was involved as the industrial partner to Skanska by delivering the

frame of the building extension.

White Design ModCell’s founding company and the architectural company that

made the design for both the Glenfrome project.

SWMAS Sout West Manufacturing Advisory Service (SWMAS) is a lean

manufacturing consultancy business, which delivers advice on

business improvement to mainly automotive, aerospace and the food

industry. They were brought in to the research project as

manufacturing consultants for the Glenfrome project. Before the

research project, SWMAS had been working with ModCell on

improving their production process in FFs.

Exelin A sister company to SWMAS and a manufacturing advisory business,

which also uses lean manufacturing philosophies as part of their work.

They were chosen as manufacturing consultants for the Battersea

project.

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45

UoR University of Reading (UoR) was brought in as a project partner to

assess the use of portable 3D technology in improving supply chain

management in both pilot projects.

BRE Building Research Establishment (BRE) is a built environment-related

research and consultancy organisation. Their role as project

participants includes to adress issues associated with the use of RFID

(Radio-Frequency Identification) in supply chain management and to

support Skanska in carrying out project management activites.

Figure 4.4 Illustration of the involvement of the project participants in the research

project

Skanska UK

Glenfrome (PILOT PROEJCT1)

ModCell/White Design

SWMAS UoR

Battersea (PILOT PROJECT 2)

Exelin UoR BRE

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5 RESULTS

5.1 The MFF concept in total

5.1.1 Deciding on off-site manufacturing and MFF

The MFF concept is by Skanska seen as a strategy for producing off-site. When asked

about why to produce off-site, the Managing Director emphasizes the quality and time

benefits that comes with it, rather than a cost benefit. It is further explained that with

off-site, it could actually be more expensive than traditional construction or at best

break-even. As such, the Managing Director emphasizes that making profit from off-

site techniques is not primarily when making a decision about using these techniques.

It is on these terms that Skanska is trying to subsidize the overall business towards off-

site production. However, it is not possible if it is too cost prohibitive; it has to come

within some sense of a budget. The main reason will instead be to eliminate the risk of

not fulfilling contractual obligations such as missing a delivery date or missing on

quality specifications. It is believed that these risks can be mitigated by putting the

construction off-site.

The Managing Director tells that when the operating and project directors are looking

at a larger and more complex job, one of the first questions they have in their mind is

“What can we do in a factory to break it down and make it more simple?”. Further, it is

explained that to consider the numbers of people on the construction site during a

constrained time is also important for Skanska when deciding on off-site techniques

and new contracts to tender. However, the Managing Director explains that with

stationary off-site factories “[…] it can be kind of rigid what you are able to put

through those factories”. It will have the advantage of being able to go for economies

of scale but with the disadvantage of having a fixed location and fixed costs associated

with it. Therefore, it can just build what it is equipped to build because of the tied

investments in inventory. An MFF however, can be able to adjust to the change of

market conditions, change of requirements and take the costs down more flexible.

The Managing Director explains that what they are doing now in the Battersea project,

they want to be capable of doing in other parts of England. They want to be able to

move the production capability to other places than just the big cities. The idea is to

bring the techniques together with some management, engineering and factory skills to

set up the factory and employ local labour.

The Managing Director states that the development of MFF is a strategic choice to

compete on the off-site market. It is explained that there is currently one competitive

organisation (doing industry, civil engineering and building construction) that is

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investing heavily on off-site production. They have made a large investment in a

stationary factory in the north of England. To avoid this organization to create a

monopoly, Skanska will have a way to produce off-site in factories that are less fixed

and more agile. There have also been some investments in the same area from other

Skanska competitors over the last five to six years, but it appears that they are

investing less because of tight finances.

The Managing Director thinks that for Skanska to stay competitive over the next five or

ten years, they should focus on manufacturing techniques that will allow off-site

production with a shorter supply chain and without the fixed costs, which MFF is an

example of.

5.1.2 Objective of the MFF concept

The MFF concept is re-evaluating the current way of producing off-site. In the project

funding application, the objective of the MFF concept seems to consist of two parts.

The first is to develop processes that enable a step-change in the delivery of buildings,

cost effectively and at scale, where 30 % savings on construction costs and time are

targeted. The second part is that it will result in a lean, supply chain orientated,

procurement and construction process for delivering low CO2 buildings at scale with

techniques applied across a range of materials and construction types. (Skanska, 2012)

In accordance to the funding application, the Lean Consultant believe that by enabling

production of affordable near-site factories, the concept can offer a unique, integrated

procurement and construction process for a low cost.

According to the Sustainability Manager, the goal is to create a temporary production

capability with the flexibility to be able to be placed anywhere next to or close to a site

and using a variety of different techniques. As such, the Sustainability Manager argues

that MFF will be to take off-site production with a more flexible approach. By bringing

in manufacturing benefits, the quality and delivery times can be guaranteed as well as

saving costs and materials. It is stated that it allows for innovation in offsite production

to be delivered, locally and regionally without significant capital investment (Skanska,

2012).

The Sustainability Manager also believes that the concept should be able to handle

different techniques and the concept therefore deals more with the process and how it

fits together rather than what to build.

5.1.3 Benefits from factory production

As MFF projects are carried out in factory environments, many advantages is achieved

compared to a traditional construction. The Sustainability Manager, Design Director,

Site Manager and Lean Consultant all emphasized that performing production in a

factory makes the production process less chaotic and more controlled than in

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traditional construction. The Design Director argues that the MFF concept is largely

influenced by the manufacturing sector which, according to the Sustainability

Manager, creates the opportunity to guarantee the quality and work with lean methods

so that the manufacturing benefits can be achieved. This is also something that is

recognised in the TSB funding application, as it states that the concept will make for

greater possibilities to work with continuous improvements than in a traditional

construction (Skanska, 2012).

In the interview, the Site Manager claims that another benefit is improved working

conditions for the workers, as they do not have to suffer the cold, they can stay dry and

have good lightning. The Managing Director also considers that the factory

environment creates an increased opportunity for innovation because of the greater

focus.

Further, the Site Manager means that material wastage is something that can be

controlled in a better manner compared to a traditional build. One example of this is

because the workstations and supplies are close to each other in a factory. The workers

will not need to take along additional material and mislay it, which can happen when

the distance between the workstation and material supply is far. The Sustainability

Manager points out that time wastage in the form of searching for equipment, which

can be spread out all over the construction site, is also something that will be reduced

in a factory environment.

Additionally, the Sustainability Manager means that a factory environment gives the

possibility to have a more certain foresight of how the project is going together. It is

explained that the weather can with traditional building cause problems with rain and

snow if the roof is not in place. With MFF, this is not a problem and the ability to

continue building can be guaranteed not depending on the weather.

5.1.4 The factory

Factory location/geographical mobility

In the interview, the Sustainability Manager explained that the geographical mobility is

an important factor for the concept. The concept is about creating temporary capability

in factory form for off-site production, on or close to the construction site. The nearness

to the construction site is also emphasized in the research project resource application

as a key to an efficient and effective assembly (Skanska, 2012). The definition of ’close’

has in the concept been evaluated to be within a 40 km radius from the construction

site with transportation distance and costs as influencing factors. The Site Manager

expresses doubt around this radius as the limit for the MFF. It is believed that to assess

the optimum geographical distance, there instead needs to be an evaluation of factors

such as availability, rent in different geographical locations and individual project

conditions. The latter is dependent on a relationship between what is being produced,

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how many units are produced and within what sort of programme constrains. The Site

Manager also mentions that a sufficient floor area and geographical labour costs are

parameters that may be of relevance in the choice of location. The transportation cost

may be less important since it has to be paid for in any case, if the factory is not within

the construction site.

However when having the factory close to the construction site, some benefits will be

gained. The Sustainability Manager points out that it can lead to savings in logistics. It

is believed that it reduces the risk to "[...] move the things around the country” which

will save carbon costs as well. The Managing Director also emphasises the proximity as

important because otherwise, problems with transportation like motorway blockings

can cause problems with reliability of the delivery.

The choice of factory building

It has been found that the core of the MFF concept is to reduce the capital cost and the

Sustainability Manager argues that it can be done by keeping it as simple as possible.

The Design Director explains that normally when wanting to prefabricate, it is

necessary to invest in a factory. This means a high capital investment that has to be

constantly utilized to be profitable. To reduce the capital cost so that this problem can

be avoided, the idea is that the MFF shall have production only in temporary factories.

The Lean Consultant thinks that barns are an example of a building suitable for the

concept. The Sustainability Manager also highlights these as appropriate and adds

farmers’ buildings, prebuilt warehouses or office spaces. The advantage with these is

that they are available to be rented at very short notice and that they can be available

for rental for short periods of times. During the interview with the Sustainability

Manager, factory ‘tents’ on or close to the construction site were also considered to be a

possible solution, which would be to keep the concept as simple as possible. The Site

Manager, however, is sceptical to the solution of having the factory on the construction

site for certain types of projects. This applies especially in cities where there is likely to

be limited possibilities of being able to erect a temporary facility at the site itself due to

restricted space. Available empty industrial units are instead highlighted as a good

solution and a possible future for the concept. As in the case with the geographical

location, the Site Manager believes that in the choice of factory premises, it is also

important to assess suitability for the project's individual needs; " My feeling with all of

this is not to become too fixated with either distance, or the type of structure, it is more

about assessing every project on its merits; whether it’s worth spending money on

building a temporary unit or whether you could make use of another one.”

An extreme case of the MFF and a version of the concept's vision is according to the

Lean Consultant that the factory is so flexible that it can be integrated into a portable

container. During the interview, it is explained that the container could be

transportable by truck and have sides that can open for access to the production line.

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When the production is finished on a construction site, the container will be

transported to the next building project. The Sustainability Manager also mentions this

kind of idea during the interview when pointing out that MFF projects can offer

portable accommodation that can be put up in car parks or in the project itself.

5.1.5 The importance of an effective start-up and closedown

Whatever type of factory premises or geographical location, it is important to have an

effective start-up and closedown to get the MFF to work. The Lean Consultant explains

that if the time for start-up and closedown of the factory are a significant part of the

total construction time, the concept has not fulfilled its purpose. The Lean Consultant

therefore considers that to shorten these times, it is critical to maximize the value

added part of the factory, see Figure 5.1. It could be exemplified with a comparison

with Formula 1 cars, which for decades has been developed to shorten the pit stops by

applying quick changeover techniques. The Lean Consultant thinks that this is

applicable also on the concept of MFF.

Figure 5.1 It is important to minimize the extent of the start-up and closedown of a factory

to maximize the value added time of the MFF project

5.1.6 Investment cost and level of technology

Since the concept rests on keeping the capital cost low, MFF in its simplest form is a

tent at the construction site with only power supply, manual tools and manual wheels

to shift units around. However, Skanska is also looking at the possibility to potentially

use robots for 3D concrete printing. The Sustainability Manager believes that these two

set-ups can be seen as two extreme opposite ends of a scale of technology used in the

MFF.

In the stage of planning the pilot projects, the project team was talking about

implementing automation in the production. They concluded however that it does not

work in the concept because it would reduce the flexibility. The Lean Consultant

explains that it is a major process when having to change in an automated production

layout whilst manual production capacity can easily adapt. Further, the Lean

Consultant believes that with introduction of technology, there is a risk that it becomes

specialized and involves a too large capital investment. The Design Director argues in

a similar way when stating that fundamental to the concept is to only use necessary

light equipment. However, if investment in machinery is necessary, the machines

MFF PROJECT

Start-up Operation Closedown

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should be mobile so that they can be moved to the next location; ”[…] otherwise, you

might as well invest in a stationary factory”.

5.1.7 Contracting and finances

The Managing Director states that early contractual involvement in the design stage is

important for the concept. It is therefore appropriate to use contractual mechanisms

that support this. The ones considered relevant are design-build, ECI (Early Contractor

Involvement) and NEC contract. The Sustainability Manager also thinks that design-

build is a traditional procurement method that suits the concept. However, partnering

is stated as the way to go forward in the future.

When MFF is procured as a sub-contract of a larger project, the Site Manager thinks

that the best way is that the same company also has the main contract. Further, it is

highlighted that a big organization with many levels involved in the project can

hamper the execution. It is a risk that the development company (MFF) is enthusiastic,

this needs to extend through out all levels or there is a risk of a lack of understanding.

As such, an organisation with fewer levels could be more suitable for the MFF concept

and a control on the management chain and partnering are the best way of working. A

flat organization will encourage a more effective decision making process and is as

such seen as the best way to get an effective production.

5.1.8 Scheduling

The Design Director believes that one of the major benefits of using MFF is the speed of

production. Both The Managing Director and the Sustainability Manager emphasize

the potential of the concept in terms of guaranteeing delivery times. Independence of

weather conditions is also a factor that contributes to the more secure timing.

The Managing Director states that the concept is about making quality products that

work the first time they arrive at the construction site. They must not cause any

disruptions to the flow on the construction site, which will eventually give a high

confidence to the construction programme. The Sustainability Manager and the Site

Manager believe that the MFF should be able to step up for a compressional project.

The concept should be able to be flexible in producing more by increasing the

workforce. In a traditional construction, an increased workforce instead would have

led to different tradesmen working over each other because of the compressed

programme. The feature of MFF will instead give flexibility to the actual programme,

which will ultimately save time.

5.1.9 Supply chain

The Managing Director explains the idea with MFF as to “[…] have a repeatable

process for setting up a factory anywhere”. That gives opportunities for shorter

logistics and shorter supply chain from the factory to the construction site. However,

the Site Manager stated that within the MFF concept, it is very important to make the

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project factory-friendly in terms of suppliers and transport. It is about getting the

supply chain to understand that factory production may set different requirements

over traditional construction and that it is important that these requirements are met.

This will then simplify production and therefore ultimately ease the process for all

parties involved in the project.

5.1.10 Workforce

MFF has the ability to be close, which thereby creates the flexibility to employ locally.

The Managing Director emphasizes the importance of using the local workforce and

teaching them the process through the support from experienced management.

The idea of the MFF is that it should be standardized to the point that the production

can be seen as a production line and the worker as a part of that. The Lean Consultant

points out that the advantage of this is that the control of the individual work is greater

than when the work is performed on site at a large construction project.

The Managing Director points out that there is a difference of skills required on a

construction site and in a factory. In a factory it is “[…] all around how you set your

process up”. It is about making the process very simple with set out steps of what their

jobs are. That includes to train them accordingly and then rechecking and testing to

ensure quality. The Sustainability Manager also argues that the production is

simplified in a factory, which allows for a lower knowledge level of the workforce. The

concept is therefore to have multi-skilled labour rather than specifically skilled

tradesmen that once in the production, gets trained into the process. The Sustainability

Manager exemplifies it by; ”So instead of having electricians you have guys that can

put electrical boxes together and plug and plate them together with each other because

you don’t need a fully skilled electrician to do that”.

The Managing Director thinks it is achievable to run a factory even with unskilled

labour. When the disciplines design, pre-construction, construction, change control

and quality assurance are right, it will be possible to train an unskilled person within

one or two days to produce repeatedly. However, it is about clarifying what type of

process structure the project is aiming for. Depending on that, the project will need

different types of skills.

The Site Manager is also optimistic about simplifying the production process to

employ unskilled labour. Just like the Managing Director, it is believed that the factors

that affect this are learning, templates, familiarity and training. It is argued, however,

that it is difficult to get away from the fact that some operations will always require a

trained person, for example to perform electrical testing. The Site Manager also shares

the same belief as the Sustainability Manager; that it is multi-trade labour that is

needed in the production, as they will be asked to perform tasks between trades.

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The Lean Consultant has a slightly different view of the concept in terms of

knowledge; it is believed that one of the advantages with MFF is the possible use of

different skills of labour within the process.

5.1.11 Product developing and design process

The Managing Director stated that discipline and control is needed in a factory and it

all starts at design. The concept needs a system where “you do your design, you lock it

down, you do your pre construction, you lock it down, you do your construction, you

lock it down”. Further, the Managing Director states that the industry, as well as

Skanska, has a lack of discipline of design changes to fit a manufacturing process, and

that it is something they need to work on.

When talking about getting a lean process in terms of design and supply, the Lean

Consultant explains that “[…] the earlier you get into the process the more benefit you

can build in to the process”. The design therefore needs to be fixed early, as far as it is

possible. The Design Director argues in a similar way when pointing out that with a

prefabrication strategy it is important to make all the design decisions early in the

process. The Site Manager argues that it is hard to assess the extent of the design

process (in the Battersea project) and for how long the design process will last into the

project. It is believed that it can become a problem in terms of late decisions and

changes. The extent of the design process changes is something that is the same for

many other off-site construction processes.

It has also been identified that the MFF concept has to offer flexibility against the client

in terms of time and design. The Lean Consultant explains that in the traditional

construction industry, it does not work to require a fixed design in an early stage. The

mentality is traditionally that it should be possible to make changes in the design along

the way. The idea with MFF is to be flexible by having a pull-system where the client

or the construction site pulls the units from the factory. However, the Site Manager

points out that the flexibility has to be within a certain parameters. As can be seen as a

response on that, the Lean Consultant argues that to succeed with late changes, it is

about finding variants in the elements of the design that can be changed in a late stage.

That makes it possible to customize in a pull-system within these variants.

The Site Manager states that all professionals (i.e. the Design Team) involved and

anyone that could have an impact need to understand the production process and how

their decisions and work, affects the production at the end. Even though designers

who have previously had experience of prefabrication, a new product (i.e. one not

previously used) introduces a new design and can make it hard for designers to fully

understand the risks. The Lean Consultant emphasizes that it would be beneficial if the

design team had knowledge about lean or close collaboration with lean expertise and

points out the importance of making the design suitable for production in a factory.

That would give possibilities to design out waste and quality defects from the

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beginning. The Site Manager argues in the same way, for a factory-friendly design, and

states that it would make the work easier for everyone involved. According to the

Sustainability Manager, traditional building techniques can include a lot of processes

and when possible, other techniques should be considered. The Lean Consultant

explains that Design for Manufacturing (DFM) is something that they have been

talking about in the MFF project. Also the Design Director points out that it is

important to think about Design for Manufacturing and Assembly (DFMA) when

using the MFF concept as the factory represents the assembly process.

The Managing Director emphasizes the importance of using techniques from the lean-

related concept of TQM (Total Quality Management) such as Poka-Yoke, within the

MFF concept. The method involves fail proofing by making sure "[…] it only fits one

way. So there are ways of doing it where you can make sure that with an unskilled

person at a factory, they will consistently build the same thing all over again." The

Managing Director indicates, however, that with this method, it is important to have

consistent quality checks at the end station.

5.1.12 Finding the right projects

Projects, scale and competition

The TSB funding application says that “MFF will be suitable for constructing buildings

of all types to demanding sustainability standards but at standard costs, greater

volumes, & with low defect levels.” (Skanska, 2012). The Sustainability Manager thinks

that as such, it will be a challenge to find the right projects to apply the MFF concept

on. However, it is believed that the concept of MFF is more about having a process.

The two pilot projects, Glenfrome and Battersea, are very different from each other in

terms of building elements and techniques. Therefore, it is argued that they together

can be seen as an example of that MFF is more about the process than what is actually

built.

However, finding a suitable project is important. The Design Director explains that the

concept requires that the value of the product is high enough, that it is repeated and

that it can be handled in an acceptable way (for example not big and heavy concrete

elements). The Site Manager believes that there are actually very few technical limits to

what can be prefabricated as long as the competition is not too high. The limiting

factors are instead in the understanding and training of people that will be working

with it. Examples of products that would not be suitable because of too high

competition are bathroom pods, kitchen pods or whole rooms. The Sustainability

Manager as well as the Site Manager see a potential problem in that the manufacturers

to compete against would have a really leaned down process for materials etc., which

would be hard to compete against in the MFF concept’s early stage. The Sustainability

Manager therefore argues that it is necessary to niche to succeed with MFF and the

niche needs to be more flexible processes. The utility cupboards are unique as nobody

has done that before and the Sustainability Manager describes it as “a little niche”.

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However, it is believed that the MFF concept can in the future be able to compete

against the specific off-site manufacturers if the process is slick enough. The Lean

Consultant argues in a similar way as it is explained that the scale is a problem in the

current situation. With a developed process, there is no reason why MFF would not

work in smaller scale in the future. The developed process just needs to be made

“really slick” by shortening set-up and shut down times of the factory (SWMAS, 2013).

Despite this, the Lean Consultant does not believe that MFFs will ever be applicable on

unique design buildings.

Level of complexity

The Sustainability Manager believes that the two pilot projects; the panels in

Glenfrome and the cupboards in Battersea, can be seen as two extremes on a scale of

complexity. It is argued that MFF will not do more complex things then they are doing

in the Battersea project. However, MFF is not for everything and it is emphasized that

complexity is not an issue by itself but when it comes to complex modular variation it

becomes an issue.

The Managing Director states that it is about looking at the competition and what can

be obtained from the supply chain, instead of looking at complexity. It is exemplified

by asking why invest in manufacturing capability when someone else is already doing

it better? Why not buy from anyone else when it is cheaper then making it yourself?

The Managing Director argues that complexity can be made less complex if it is broken

down into smaller sub-assembled components.

5.1.13 The process of developing the concept

Potential and market

When the Sustainability Manager were asked about the potential of MFF, it was

stated that the potential is huge and that there is potentially huge savings to do.

The Site Manager also sees the future of MFF as positive.

For future MFF projects, Skanska has been talking with Ministry Of Defence about

possibly building prisons. The Lean Consultant also highlights hospitals as an example

of a building that could be suitable for the MFF concept, since they are fairly

standardized. The Managing Director adds residential, primary and secondary schools

and also large pharmaceutical company buildings to the list of potential markets.

The next step – toolkit and decision-making matrix

The research project plans to create a decision-making matrix and a toolkit as a report

to take advantage of important lessons from the pilot projects and facilitate decision

making in future projects. The decision-making matrix will handle decisions

concerning if a specific project is suitable for MFF to assess if the concept is viable to

implement. The tool-kit on the other hand will include when to set-up, how much

lead-time that is needed and other things to think about in the start-up of the process.

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The Managing Director states that the tool-kit is a good start for the development of the

concept. It is useful until they find something else and better. The Sustainability

Manager points out that MFF is a conceptual idea at this point and that it has not been

done before. He says that the idea is to have a stepped approach rather than to do all at

once. He emphasizes it by “learn and move forward to the next and add on to that”.

Challenges and difficulties

The Lean Consultant mentions two of the current challenges for the MFF as meeting

the traditional construction process and making a commercial offering for big

construction companies. The Sustainability Manager emphasizes the fact that viability

of the concept needs to be proved. He feels that there are frustrations with the

Battersea project as it has struggled with various problems in its start-up phase. The

frustration lies in that the project team now wants to see the full potential of the

concept. The Sustainability Manager is slightly concerned that the project will not live

up to expectations to prove that the concept is working. This is needed before the

concept can be adopted in future. One of the Sustainability Manager’s main concerns is

if the process will be very close to a traditional build, which would cause a problem

with being competitive enough. However, it is believed that the way forward is to get

the process leaned down closer to the MFF philosophy. The Sustainability Manager

summarizes it as to avoid bottlenecks, slick material and waste and have a workforce

that are multi-skilled instead of specifically skilled. The Managing Director agues in a

similar way when stating that for future projects, Skanska as an organisation needs

some success from MFF so that people want to build from that. It is not necessarily the

profitability of the Battersea project that is crucial; it is more about being able to show

control over time and quality.

The Managing Director also considers the difficulty with the concept to be that the

project participants are “builders”. They do not have experience about factory

production and what it means to design for manufacturing as well as what it takes to

set-up, control and run a factory. The Managing Director sees DFM and BIM together

with early involvement as crucial for being competitive when producing off-site. With

DFM, it is believed that it is about gathering the right disciplines for a proper use of the

method.

Further, the Sustainability Manager thinks that there will be a challenge to find the

right projects to apply the MFF concept on. He believes the tricky part is to come up

with the basis for decision-making through the decision-making matrix they are

developing. The Managing Director also states that Skanska as an organisation will

have to identify where else MFF is suitable.

Although the Managing Director believes that the concept has a potential, it is argued

that “it will only be as good as its speed in which it is prepared to move against what

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else it can compete with.” As such, it has to demonstrate that it is better and can help

the company become more competitive than with every other option they have got.

For example, The Managing Director keeps getting told about future technologies such

as the 3D printing technique. However, if Skanska decides not continue with this

concept (i.e. specifically the manufacture of utility cupboards), the Site Manager is sure

someone else will. A continuous development is essential in order to remain

competitive. Also, to produce something new and unique is emphasized as something

that in it self leads to risks.

5.2 Pilot project 1: The Glenfrome project

5.2.1 Contracting and finance

The Design Director considers that the project had contractual issues rather than

technical production issues. Although the project team were partners in the research

project, the building was procured as a traditional build, which contributed to a more

restrictive approach between the participants.

The Lean Consultant states that the MFF currently requires quite a large project to be

profitable. It is doubted whether the concept would have been used in the Glenfrome

project if it had not been a research project. It is stated that the project was not cost-

effective because of the long start-up and closedown of the temporary factory,

considering it was such a small-scale project. Part of that is due to that the start-up of

the project was not planned and performed in the most efficient way possible. In the

beginning, the learning was while building and a big part of the time was therefore

non-value adding. As such, the Lean Consultant believes that to be able to use the

concept on smaller projects, more work has to be done to shorten the start-up and

closedown period of the factories.

5.2.2 Scheduling and supply

Because the object was a school, it was available for construction only during the

summer holiday, which was less than four weeks (CIOB, 2013). It was therefore very

important to have a short construction period. With the MFF concept it was possible to

minimize the time spent on site for assembly. The Design Director states that one

classroom was assembled in just 1 ½ day and for the whole extension it took seven

days.

In the institutional article, Skanska’s Operations Manager said “I think the ModCell

method of construction is the only way we could deliver a sustainable building in such

a tight timescale,” (CIOB, 2013).

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As been mentioned earlier, the research project intended to implement ICT to the

project to guide the participants and involve innovative suppliers. However, that did

not happen in the Glenfrome project because of a lack of quality in the BIM model.

5.2.3 Investment cost and level of technology

The wall panels were produced in a farmer’s barn, which was rented for the duration

of the project and the equipment in the production was basic and manual. That meant

that the project required a very low capital investment and as such, the Lean

Consultant sees the project as a very simple version of a MFF.

5.2.4 Product developing and design process

The building was erected with laminated timber and straw bale panels both for the

walls and the roof. The timber frame was glue-lammed and pre-cut from a local UK

supplier, and the panels were then pre-assembled as sandwich elements with internal

OSB boards and external breathable boards. Thereafter, an external rendering with

breathable render was made on site and complemented internally with dry lining

(ModCell, 2014).

White Design made the design for the wall panels. As they have founded ModCell,

they had experience of prefabrication and the building system they where using for the

Glenfrome Primary School. Because of that, they also knew about the importance of

design freezes. The Design Director therefore states that the project was lucky not to

have any design problems in the execution.

The Lean Consultant thinks that White Design’s experience of prefabrication is shown

in the standardization of the panels. In total, there were 18 different sizes of the

building element, but the construction was the same regardless of size.

5.2.5 Workforce

In the execution of the project, there were two highly skilled operatives and two

apprentices. The apprentices could do certain tasks, but not all of them and all of the

operatives were building individually. That resulted in the apprentices’ constantly

kept having to ask the skilled operatives for clarification. Because of a need for the

apprentices to learn about the process, they got to do the assembly whilst the skilled

ones were bringing in the materials and controlling the work. Therefore, the utilization

of labour was not optimal.

5.2.6 A leaned process

There was no implementation of lean principles on the Glenfrome project as the

production had already started when the lean consultants were introduced and the

production time was very short. However, the improvement suggestions made are to

be included in the development of a possible future and similar pilot project. (SWMAS,

2013)

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It was proposed that after implementation of improvements, in the future, the days of

producing 10 wall panels would be reduced from ten to five. The main proposal from

the lean improvement work was a suggestion to change the layout of the factory to a

manufacturing line with standardized workstations and related instructions. Instead of

having four workstations were every worker assembled one whole wall panel each, it

was suggested to split the production process up to three production steps. These

workstations would be responsible for different production activities and the

operatives would be assigned to them depending on skill level. That means to change

the process from ’batch and queue’ to a continuous flow production line with balanced

cycle times for all stations. (SWMAS, 2013)

The proposed production layout would have required overcoming the challenge of

moving the panels between the stations. As the panels were big, the equipment would

therefore have meant some capital investment. The Lean Consultant states that when

investing, it is important to make sure that this investment will not be too large so that

the idea of MFF with a simple set-up is waived.

5.3 Pilot project 2 Battersea: Start-up and production process

5.3.1 Deciding on MFF

The Managing Director explains that the decision to produce off-site was for the

Battersea project because of concerns for lack of space on the construction site. To

carry out the project on site would have meant that many different trades would have

worked on top of each other. Producing off-site meant a better solution as it provides a

controlled environment.

5.3.2 The choice of factory location and building

The Sustainability Manager states that a factor for choosing to make cupboards as a

MFF project was the opportunities that came with the unit in Slough. The rent was a

good deal and the fact that Skanska already had an existing, stationary off-site factory

with the skills and workforce available at the site presented a good opportunity. It

gave the advantage of having the skills and understanding of off-site manufacturing

close by, which was seen as a resource to back up the concept. It is pointed out that the

MFF concept is a conceptual idea at this point; it is something that has never been done

before. The Slough factory solution is to avoid adding extra complexity that would

have come with creating a temporary factory on site. The Sustainability Manager states

that one disadvantage with renting units like the one in Slough is however, the rental

times that are a minimum of six or 12 months.

According to the Site Manager there was not much emphasize on the planning of the

location of the factory, it had to be more a coincidence than a considered choice. The

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unit was available, it seemed to suit them in size and it happened to be close to

Skanska’s existing factory for MEP prefabrications. When discussing the solution of

using a tent nearby or on the construction site, the Site Manager believes that it would

not have been possible. At least, believes it would have become much more expensive

due the cost of the set-up with requirements such as a smooth floor and the size of the

factory.

The Managing Director considers that the distance between the factory in Slough and

Battersea can be considered 'close'. A distance of 40 km (refers to an approximately

distance from Slough to Battersea) would not bother, but the Managing Director states

that if getting a question to produce cupboards 200 miles away, the answer would be

“No way”. The risks with the transportations would be too big. As well as with the

planning of location, the Site Manager indicates that there was not much emphasis on

planning the factory layout either before choosing the unit. They have now realized

that the unit is too small and that a bigger working space would have given possibility

to produce the cupboards more effectively.

5.3.3 The production

The production process is described in Appendix A a simplified version is presented in

Figure 5.3. What is described in the appendix is an approximate description of the flow.

Observed was that the procedure of work could vary due to waiting for decisions,

components, a need to prioritize and to rework (see causes in 5.3.8 Difficulties and

problems).

The work is being done where the cupboard stands. Most of the work is done

manually with no more advanced tools then would be used on site.

The number of variations of the utility cupboards has changed during the start-up of

the factory due to design changes. The Site Manager stated that in the beginning the

discussions were about around 4 different variations. There is now about 4 or 5

different sizes of the cupboards and in total about 48 different variants to be produced

in the factory (which can be seen in Appendix A). This number was partly understated

from the start due to a lack of knowledge.

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Figure 5.3 Simplified maps of production process for cupboards in the

Battersea project.

5.3.4 Workforce

The majority of the work in the factory is being done by Skanska’s own labour

although some works are outsourced (boarding and painting). Skanska’s workforce are

plumbers and electricians and they are also doing other things that are not typically

work they are trained to do, for example moving cupboards around and making

templates for drilling holes.

Skanska’s labour was recruited from an agency that Skanska uses. When searching for

labour, the agency was told about the project and what type of labour the project

needed. They were also told that the operatives would be doing both electrical and

plumbing work and that they would be working in the project as a team (i.e. multi-

tasking). The Site Manager states that they have had to try out a number of operatives

in order to the ones that meet the criteria. This factory is still relying on skilled and

even multi-skilled labour because of the complexity of the project. According to the

14. Wrapping

13. Pressure and electrical test

12. Insulation of water pipes

11. Complementing electrical work

10. Installation of Passive Infrared Sensor and lighting

9. Installation of water pipes and meter, drainage and access hatch

8. Installation of Mechanical Ventilation with Heat Recovery

7. Installation of electrical sub and trunking

6. Installation of Heat Interface Unit

5. Taping, jointing and painting

4. Boarding, plasterboard

3. Insulation top panel

2. Boarding, plywood

1. Steel frame

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Site Manager they succeeded (so far) with having the right skill level with the labour in

the factory for this project. The Managing Director also states that having unskilled

labour was not a goal for the Battersea project.

The operatives have been included in finding ideas and improving the process. Ideas

that appeared good have been tested and the ones that worked well have been taken

forward and implemented in the production process. When issues emerged it is dealt

with in the first instance with the person involved and if there is something that affects

other people, it is dealt with in the group. The Site Manager also points out that the

work done by the group, in this way, has been a success story.

5.3.5 Scale, contracting and finances

The Site Manager states that to find the minimum production quantity to go through

with a MFF project, and for this it is necessary to have data. Since Skanska have not

done something similar before, they had no data to use for calculating and planning.

Which is the appropriate minimum order quantity to make the process economic then?

The Site Manager explains that this is something that the team are thinking about all

the time. However, it is believed that Skanska considered the 866 units that where

possible at beginning was considered to be sufficient and would allow for a certain

adjustments in numbers. Also the Lean Consultant states that this project, in theory,

has a big enough scale, even if the set-up and running at the moment is not efficient.

The importance of a lean and efficient start-up and closedown to succeed with MFF is

pointed out.

According to the Site Manager, Skanska wanted to produce all the utility cupboards for

the project in the factory to get as big scale as possible and for increased repetition.

This has not proved possible due to the design of some of the spaces within the new

build, which are creating irregular cupboard spaces, not feasible to build except `in-

situ`. Approximately 1/3 of the units will not be made in the factory. According to the

Site Manager, that is an indication that the design team having a lack of understanding

of the pre-fabrication requirements.

The project as a MFF is purchased with a fixed price and a design-build contract. The

Site Manager stated that this is one of the reasons for a commercial risk the project

implies. The Sustainability Manager states that the fixed price is based on traditional

way of building the cupboards, and should in this case be beneficial.

5.3.6 Management and planning

The project’s site manager (the interviewed Site Manager) is the only one working with

management in the factory. In purchasing, the site manager has support from the

Skanska organisation. Other management support observed are lean consultants from

Exelin and managers from Skanska which give advice in some decisions.

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The Sustainability Manager points out the benefit of achieving timing for the main

project; they will almost be able to guarantee that the cupboards will turn up in time

and not be weather dependent. The Lean Consultant states that this project should be a

good example of a pull-system with the client or the construction site pulling the

modules from the factory. This makes the concept able to handle changes in the

delivery times. However, whether this project can be considered as a pull system is not

established.

In this project, they have been flexible in the production and they had that approach

right from the beginning. The Site Manager explains that they did not think “this is the

way we are going to do it, and we’ll stick to it rigorously”, because they knew that was

not going to work. The plan, in agreement with the client, was to deliver 20 units per

week to have coordinated transports with bathroom pods from Germany. That meant

producing 20 units per week in the factory. However, complications arose from

groundwork on the construction site causing delays. As such, Skanska has been forced

to rent additional storage for the cupboards, since they have had to continue producing

20 units per week. This is to ensure the ability to deliver all contracted units in time at

the end. As a result, Skanska has had problems in finding a unit for storage, no ability

to deliver and lack of space in the factory, which have caused congestions in the

production process.

The planning for appropriate labour appears not to have had a big importance since

other things have been taking more focus. However, it has been indicated that they

needed more labour than they planned for. The taping, jointing and painting as well as

the boarding are processes that are not going on continuously. They are important and

especially the painting, which is a bottleneck, is relying on the hired firm to be flexible;

to appear and to perform the work so that it fits the rest of the process. Since the work

of the subcontractors is not consistent, they cooperate with trying to find a way that

works well for all of them. The boarding is an example of that, originally it was

decided that six frames would be boarded each time the team of boarders came to the

factory. They discovered it went faster than they planned for and it should actually be

a minimum of eight each time, possibly 10. The next step is the tape and

jointers/painters, and from their view it is more economical if they make 20. The Site

Manager thinks it is not possible to do 20 at a time, but they are going to try to

manoeuvre things so that it fulfils other supply partner’s needs.

The Site Manager thinks the extent of the learning period was underestimated.

However, it is stated that the advantages of temporary factory production are clear

compared to carrying out this work on site. An example of such an advantage is the

control of quality. Skanska are still trying to get numbers (hours and costs) required for

each unit, but complications make it hard to get the numbers correct. The Site Manager

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refers these complications to constant changes in the design, which makes it hard to get

the numbers static.

As been previously mentioned, the research project intends to implement ICT or BIM

in the concept. However, that did not happen in this project. Instead they had some

discussions with BRE about possible test application of RFID in the form of a ‘Tag and

Track’ system. The cupboards would then be tagged and scanned with handheld

devices. Such a system has several potential functions. Discussed for this project was

primarily including dates and quality checks.

5.3.7 Product development and design process

The design process was carried out in a traditional way. The client’s architect produced

the design for the cupboards, in particular the sizes, and the ingoing components were

specified by the client in the electrical and mechanical specifications, via their own

mechanical and electrical consultant. Several stakeholders have since had interest and

wanted to have influence on the design of the cupboards; Carillion’s (Main contractor)

designer, Skanska’s engineers/designers and Skanska in the factory that are

constructing them. Since Skanska got the contract on constructing the cupboards, the

design has developed. The Site Manager describes it as a “three way process”; The

client’s designer made a first design (and later adjustments), Skanska’s

designer/engineers have refined the design to make it buildable and then the factory

came with important input from the production. As it has been built, the factory

reported back and forth with designers to improve the design.

The design work has been lasting from the beginning and is still going on (almost at

the same time as the first cupboards should leave the factory). However, the time that

has to be spent on design has decreased compared to the beginning of the project. A lot

of the communication has taken place when issues have occurred.

It is not known if the designers have experience of off-site production. However, the

Site Manager believes that the fact that the cupboards are a new product makes it hard

to fully understand the risks.

5.3.8 Difficulties and problems

One reason for the factory lacking space is because they have more than the planned 20

in production. Changes in schedule and design issues have made it impossible to finish

the cupboards and complications with renting storage are reasons that the factory had

up to around 40 cupboards in the factory at the same time. That high number was a

result from that pausing the production was not an option because they could not

afford to loose time.

The absence of “design freeze” has also been a problem in this project and the

Managing Director states frustrations about the lack of discipline concerning design

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changes in the project. The Lean Consultant points out that the problem with late

design decisions is based on a traditional construction mentality, where it in many

cases is okay to make changes later in the construction process. The Site Manager also

believes that the design decisions were causing the biggest problems for the

production, problems that were underestimated by the site team. Decisions where not

made early enough and made too late into the production process. Part of this has

occurred due to the number of participant’s wanting/needing to have impact on the

design as one of the reasons for the design issues. As an example, the Site Manager

explains that they are currently discussing changing of colours in the cupboards; at the

same time as the first ones are about to leave the factory.

The design changes have affected the suppliers in a way they have had to adapt to. The

suppliers are both given problems but have also been causing problems to the process

(i.e. lack of supply control and the over-supply of materials, which intern causes

storage issues). There are higher demands on the suppliers that deliver to the factory

than to traditional construction. That is partly because the goal of MFF is to reduce the

processes in the factory. The distribution boards is an example of that; to cut and fit all

the parts going in it was time consuming and they wanted it to be delivered with all

the bits in it. If the suppliers do not usually do this, it can become a problem. Another

supply issue is that the sub contractors all have different ideal economical quantities,

which is mentioned in 5.3.6 Management and planning. The Site Manager states that they

are trying to satisfy the needs but that it is not always possible.

When talking about the supply chain of the factory, the Lean Consultant makes a

comparison with the car manufacturing industry where they are succeeding to get all

components in the right time. If they stop producing cars, the seats will not continue to

be delivered to the factory. That is what has been happening in the factory as the

boilers where bought in a big volume and they kept being delivered although it was

found that the cupboards should have another boiler. The Lean Consultant points this

out as an important lesson for future projects and that it should be in the tool kit. It is

also pointed out that the supply has to handle the unpredictable design changes.

Currently, it is a push system that needs to be changes into a Kanban and pull system,

according to the Lean Consultant.

The design is done in a conventional way with plasterboard and plywood on a steel-

frame. The Site Manager points out that the actual cupboard (without the ingoing MEP

components and units) has contributed to the most difficulties in the production. The

main issue, according to the Site Manager, is the fact that the production process for

the actual cupboard contains to many steps and is very time consuming. Issues such as

space taken up, dust created by the forming of holes and penetrations, even with the

working of the pre-cut boards, and drying time for the tape, jointing and painting

come with it. The Site Manager states the design needs to be developed into a much

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more slick piece of design that is more factory friendly. The Lean Consultant points out

the importance of choosing construction methods according to Design for

Manufacturing (DFM).

The construction technique used also makes the process depending on hired painters

and boarders, which is not optimal according to the Site Manager. The best way would

be to find other techniques where these processes are not needed. The Site Manager

further explains that ideal would be to not be dependent of external labour at all and

have more control within the organisation, the future is to find other techniques more

suitable for a factory environment. The Sustainability Manager agrees about the

construction technique not being suitable. It takes a lot of processes and are a bit of a

bottleneck, which slows down the built and have cost associated.

The Site Manager describes the stage that they are at as still in the “preproduction”

phase and that they must constantly work to evolve the product to improve the

production process. The issue is the fact that they are still in this phase at a late stage.

5.3.9 Problem and difficulty matrix

Table 5.3 reports problems and difficulties that have been encountered in the Battersea

project. It is a summary from a more detailed matrix in Appendix B, which also presents

its causes, consequences and what actions have been taken. The problems and their

origins are based on observations from visits and information from performed

interviews.

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Table 5.3 Problems and difficulties that have occurred in the Battersea project with the

origin of the problem

No. Problem Origin of problem

1 Steel frame not designed with space for pipes Design

2 Bolt and nut on the back of the cupboard are too

long Design

5 Steel frame thick, difficult to install plywood Design

3 Specified and bought ventilation units did not meet

the noise requirements Design

4 Dirt on finish of the cupboard could not be cleaned

due to choice of colour Design

6 Washing machine measure too deep for the

cupboard Design

7 Decision about insulation lingers Design

8 Flushing nozzles to pipes hard to access on -site Design

9 Mounting of electrical trunking linger due to late

decision media content Design

10 Holes in pre cut top panels causing problems and

waste due to its complexity in variations Design and production

11 Plasterboard pre-cut by supplier in wrong size Production

12 Drilling plasterboard in top panel damaged the

insulation Production

13 Poor quality, rework that could be linked to an

employee Production

14 Unevenness on the interior finish, rework jointing

and painting Production - Subcontr.

15 To much material delivered, lack of space Material supplier

16 Storage for finished cupboards is too small, change

in schedule from client Client

17 Too crowded in the factory as completed cupboards

could not be shipped out Combination

5.3.10 Improvement work and lean improvements

The lean expertise was introduced to the project in a late stage and had limited ability

to influence the design. The Lean Consultant believes that an earlier involvement

would be better and that the reason they got involved late was the habits of traditional

built. The Lean Consultant points out that they have learned from this and will in the

knowledge report point out that the lean consultants should be involved earlier.

However, some improvements have been made and examples are;

Minimize the number of variations on bolts and nuts from about 20 down to

two

Using coloured stickers on the cupboards to visualize delivery dates

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Labelling shelves for components and material (plans to introduce a Kanban

system with cards)

Reduced wastage of materials has been achieved by having pre-cut

plasterboard and plywood delivered in the correct size

Together with the lean consultants involved, an alternative way of producing and an

alternative layout was discussed in the start-up of the factory. That would be to create

a flow where the cupboards move and the working station stays in place. However,

this was not considered feasible since they have not found any solution to move the

cupboards smoothly and because of the lack of space.

There are plans to change the traditional steel-plywood-plasterboard construction into

one that could come in flat packages. The solution of a construction with a flat-pack,

just bolted together would save a lot of time, effort and time according to the

Sustainability Manager. According to the Site Manager it would also make the

production less dependent on several external suppliers as well as make the process in

the factory easier, i.e. “factory friendly” by;

Reducing the number of processes

Reducing the amount of materials being used

Possible weight savings with easier manageability of the product

Less storage space requirements

Reducing dust and waste generation

Creating greater control of the product at the factory

Faster build times

5.3.11 Reflections on outcome so far and potential for improvements

The Site Manager states that they have had very steep learning curve. When

introduced to the project, it could not be imagined how much there was left to do to

get it started. The Site Manager explains that the information was in the beginning

spread among too many different people who had been involved. It was hard to pull

all of this together and to use input and experience from those involved in the project.

During (the authors) site visits, it was experienced that the site manager had a lot of

knowledge and lessons learned about the whole project, from the overall concerns to

all the details.

A concern is that what is shown in the Battersea project so far has shown minimal

benefits. The Managing Director expressed some concerns when visiting the factory in

December (the first cupboards had still not left the factory). As such, it is stated that it

needs to be improved control with discipline around changes of design and a work

area looking more like a factory cell.

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According to the Managing Director, the production process is still quite manual in the

Battersea project. It is believed that there is a great potential for development by

simplifying and shortening the supply chain and assembly process. The Managing

Director also points out that they have got a good design and production management

in the project. However, it is also stated that there could be improvements.

The Managing Director likes the innovations that are coming up in the factory

environment with new materials that can be outsourced to specialist suppliers. This is

something you would never get to if they had gone with traditional means in the

factory. Instead it is now about creating an environment where people are looking to

see how they can do the process better.

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6 ANALYSIS

6.1 MFF as an off-site strategy

It has been found that MFF is a concept that involves prefabrication on or close to the

construction site. It has been observed and emerged from the interviews that rather

than being a construction process, the concept is about having a manufacturing process

in a factory environment. The process involves design, manufacture and/or assembly

of parts into a final product, either away from or on the construction site. This means

that the MFF concept can be considered to meet Jallion and Poon's (2008) definition of

both prefabrication and preassembly. That in turn indicates that MFF can be seen as an

off-site production strategy or a method in MMC, both as defined by Gibb (1999).

In the cases where off-site fabrication or off-site production are applied, it is mainly

about stationary factories with continuous production processes. MFF uses instead

temporary factories for temporary manufacturing. The temporary part of the concept

gives an individual character among current off-site production strategies. That

individual character is also the reason why the research project received a grant from

TSB, as the purpose was ”trying out new approaches to reduce time and waste”.

Also FF, SFW, and FFF are production strategies characterized by temporary

manufacture in factories on or near the construction site. All three concepts have

similarities with MFF as the mobile factories in the FFF concept can be seen as a type of

temporary factory. Where possible, the MFF concept should therefore take the

opportunity to learn from these. That can help to guide the further strategic

development of the concept.

6.1.1 Objective of MFF

To understand if the work with MFF follow its objective, it was considered important

to gain a clearer picture of what is expected of the concept. What was interpreted as

objectives that emerged during the interviews have thus been compared with the

funding application's goals for the MFF, see Table 6.1a. The summary shows that there

are different interpretations of what is expected of MFF as a concept.

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Table 6.1a A summary of what has been interpreted as objectives of the MFF concept during

interviews and from the funding application.

Source Objective

TSB funding application (Skanska, 2012)

A lean, supply chain orientated, procurement and construction process for delivering low CO2 buildings at scale with techniques applied across a range of materials & construction types.

To develop new processes that enable a step-change in the delivery of buildings cost effectively & at scale; 30 % savings on construction costs and time are targeted.

Managing Director The main reason is to eliminate the risk to not fulfil contractual obligations such as missing a delivery date or missing on quality specifications.

Sustainability Manager

To create a temporary production capability with the flexibility to be able to be placed anywhere next to or close to a site and using a variety of different techniques.

To take off-site production with a more flexible approach by bringing in manufacturing benefits so that the quality and delivery times can be guaranteed as well as saving costs and materials.

Design Director To create a sustainable economical way of prefabricating buildings that can handle different sort of building techniques and elements.

Lean Consultant Offer a unique, integrated procurement and construction process for a low cost.

From the summary, it can be discerned that most sources mention cost savings in some

form. However, the Managing Director does not, and instead of cost savings, believes

that the goal is to ensure delivery time and quality. The Sustainability Manager

highlights all three as an important part of the concept, while the funding application

enhances cost savings and the quality aspect through 'low defect'. What is noteworthy

in this case is that all three sources are related to Skanska, which could indicate

differences internally regarding expectations on cost savings. That sort of

fragmentation has by the study of Goodier and Gibb (2007) been found to exist for off-

site in general. The MFF objective of 30 % cost savings might seem ambitious since the

Managing Director stated that off-site techniques in many cases can be more expensive

than traditional, or at best break even. That the Managing Director has a position in the

company that is important for strategic decisions indicates that eliminating risks could

be seen as more important than cost savings. However, regardless of the internal

priority, ensuring delivery time and quality as well as saving costs all seems to be

objectives for the concept. These objectives are the same as the most mentioned drivers

for off-site production in general. It is reasonable as the concept is an off-site strategy.

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Something that is also highlighted in the summary is a hope for the concept to be able

to use different off-site production techniques. Further, three of the five sources

emphasize the concept as something unique or new by expressions such as ’enable a

step change’, ’offer a unique’ and ’a more flexible approach’. This applies with what

has been stated above regarding the individual characteristics of MFF among other

current off-site strategies. Although, this can be considered to be a feature rather than

an explicit objective. The ’uniqueness’ is also reflected in the funding application,

which states that the MFF concept is based on FFs, which is considered to be ’a novel

construction process, allowing greater freedom to innovate’. The two concepts

therefore have a lot in common, which can be distinguished by looking at the FF’s

objective in Table 6.1b. The table presents a summary of what can be highlighted as

objectives and the authors' interpretation of them in keywords for the different

production concepts; MFF, FF, SFW and FFF.

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Table 6.1b The objectives as presented in the previous chapters and the authors'

interpretation of them in keywords for the different concepts.

Concept Objective Keywords

MFF See Table 6.1a

Cost savings Different techniques Guarantee delivery time and quality

Flying Factory (FF)

The least amount of money we could invest, but still do prefabrication. The Flying Factory only exists to deliver the project

Low investment Prefabrication Temporary

Swedish field workshops (SFW)

Create an effective environment and cost conciseness workplace which emphasizes on a good working environment

Efficiency Cost savings Good working environment

Flexible Field Factory (FFF)

To create a building manufacturing paradigm for an open system of products and components through manufacturing in factories and on site. The project also aimed at combining design with highly efficient industrialised production by using robotics, ICT systems and new material and technologies amongst others.

Open building system Off-site production Industrialisation Automation Technology

From Table 6.1b it can be stated that the objective of FFF has a different character than

for the other production concepts. It focuses heavily on the technical aspects of the

concept and has not a pronounced market strategy in the objective as the others. An

explanation for this can be that it is still in the conceptual stage.

What can be distinguished is a common factor in low cost (i.e. cost savings and low

investment) for MFF, FF and SFW. This indicates that although the priority of saving

costs is unclear within the MFF concept, it is important for temporary factories as a

whole.

6.1.2 Compete with flexibility through low capital investment

It is obvious that it is fundamental for Skanska to make MFF commercial. They want to

create a strategy for being competitive in the off-site market. To compete, Skanska is

not investing in stationary factories as the competitors. Instead, they are developing

something that can complement the weaknesses that a stationary factory has against

the market needs. Typically, when a stationary factory makes investments, they gain a

more efficient production and can go for economies of bigger scale. This however,

means less flexibility to react on the demands from the market, as stated by Venables et

al. (2004). That is because investments include costs and therefore, stationary factories

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strive for a continuous level of utilization to make the investment viable. Also, a

stationary factory with high capital investment becomes sensitive to economic

downturns if it is not able to lower the fixed costs. The Managing Director describes

that MFF on the other hand, have temporary factories that can start and close in pace

with the market demand. This results in flexibility in both duration and the scale of the

projects. It is therefore believed that MFF is a way of producing off-site less fixed and

more agile. The Sustainability Manager describes it as off-site with a more flexible

approach, making the concept more responsive to the market. A similar need for

flexibility has through MM and FFF been identified as important for the future

competitiveness in both the manufacturing as well as the construction industry.

As MFF is flexible in the location, it gives possibilities to make strategic choices

depending on the market demand and distances for transports and suppliers. Neale et

al. (1993) have even stated that for stationary factories, this distance can be a limitation

in the use of off-site production. The distance that an MFF should have is set to 40 km

radius, but a limit is not important. The geographical location is instead of

transportation cost, dependent on some prerequisites that have been identified as what

is being produced, production scale, factory floor area, delivery programme and labour

costs. However, having the factory close to the construction site will mitigate the risks

of delays due to transportation.

According to the Managing Director, the techniques, management, engineering and

factory skills will for MFF, be brought from other locations. It means that the facilities,

equipment, labour and suppliers will be tendered on a project basis. This results in that

a MFF project does not have the same advantages as a stationary factory from building

long-term relationships with the supply chain and labour. A stationary factory can give

the labour long-term motivations through secure jobs. The MFF concept has a complete

or near complete turnover of the labour between the projects. That can, in accordance

to Argote and Epple (1990), mean loosing organizational knowledge and will be a

competitive disadvantage relative to stationary factories.

Further, the Managing Director also emphasizes that stationary factories can have a

disadvantage of being fixed as they can only build what they are equipped to build.

Capital investments in stationary factories can be made in specialized equipment to

improve efficiency and be able to handle greater scales, but can then be limited to a

specific technique. Fundamental for MFF is to keep the concept as simple as possible so

that it can handle different off-site production techniques and therefore be flexible in

the production technique offering. However, to change production technique does not

allow long-term improvement work and without possibilities to invest in equipment, it

can be hard to compete in efficiency against a stationary factory.

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However, it is important to recognize the prerequisites and utilize the advantages that

come from producing in a factory environment. Benefits identified from literature and

interviews are summarized as:

Control over quality

Conditions for using efficient processes and production techniques

More precise time

Reduced waste in time and material

Climate proofing

Health and safety improvements

The benefits listed above can gradually and continuously be improved in a stationary

factory. A temporary factory on the other hand must find a way to take advantage of

the benefits rapidly and within a limited time. How MFF succeed in utilizing the

benefits quickly enough becomes crucial in order to compete against stationary

factories.

6.1.3 MFF as a process applied on projects

That MFF is about a process rather than projects have been highlighted through the

concept's objective and statements such as “[…] having a repeatable process for setting

up a factory anywhere” by the Managing Director. The goal seems to be to standardize

the way in which setup, operation and closedown are being done, see Figure 6.1. As

such, the concept is about a standardized process of applying temporary factories in

projects. However, as there have only been two pilot projects, a general model with

defined steps for the MFF process is still under development and intended to be

summarized in the on-going work with the tool-kit. A well working experience

feedback is fundamental for the development of a standardized process for start up,

operation and closedown of a MFF factory.

The process thinking can be seen as more obvious in a stationary factory with a

continuous process. In a MFF, the temporary part makes it more complicated since that

makes it go on in time-limited projects that give other prerequisites in many aspects.

As can be concluded from the study of Gibb (1999) and Venables et al. (2004), off-site

production means that new strategies and new ways of managing the production must

be developed, which also applies for MFF. Since the professionals working within

these projects can have a background in traditional construction, the way of thinking

should be different and changed into process thinking.

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Figure 6.1 The MFF concept is intended to apply a standardized process for start-up,

operation and closedown of temporary factories in projects

The SFW concept has a process similar to MFF with a distinct start-up and closedown

that follows the projects which the factories are erected for. The importance of a

recurring process that reaches between the projects is also found for the FF concept.

However, since FF is limited to handling just straw bale panels, the process steps of

start-up, operation and closedown will not differ. As MFF should be able to handle a

variation of different techniques, it adds extra complexity to the process. The FFF

concept differs from MFF as it is not explicitly temporary with a complete start-up and

closedown phase. The focus is instead on mobility and reconfiguration, which gives a

process of reconfigure, operate and move the factory. The process of FFF can therefore

not be direct assimilated with the current process of a MFF. However, if MFF have a

future in the direction of investing in automation, it will have a more similar process to

FF and FFF.

6.1.4 Scale and repetition

Repetition is fundamental for standardization, which in turn is fundamental for an

efficient off-site construction. This has been shown by the repetition and unit cost

curve presented by Gibb (1999). Although it only applies for that specific case, the

author states that there is a similar trend for other off-site production processes. Since it

has been concluded that the MFF concept is an off-site production strategy, finding a

sufficient number of repetitions should be equally important for the concept. However,

Gibb (1999) and Neale et al. (1993) as well as the examples in this study has shown that

the ‘right’ or ‘minimum’ number of repetitions is depending on the project

prerequisites. Difficulties to find an exact minimum and optimum will always occur.

However, with increased experience, data will be accessible that can facilitate in

calculations and assumptions.

Standardized process for start-up, operate and close-down

Start-up

Operate

Close-down

Start-up

Operate

Close-down

Start-up

Operate

Close-down

MFF project MFF project MFF project

Management

and engineering and factory

skills

Experience feed-

back

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To find a big enough repetitive scale is considered to be a problem for MFF as well as

for other off-site strategies. The Battersea project represents a project of large scale with

its nearly 600 units. MFF is also believed to have a future with smaller scales, when the

process is ‘slim’ and ‘lean’ enough to be efficient. Duration and extent of complications

of the start-up in proportion to the whole project cannot be too large if MFF is to be

viable on small projects. The Glenfrome project is as an example of a small-scale

project. Even if the results from Glenfrome can not for sure show success (because of

the authors limited access to data), it is an example of a small scale project where the

process to set-up, operate and closedown is much slicker than in the Battersea project.

As such, it seems that the scale needs to follow how successfully the process can be

made slick and agile.

The markets highlighted as potential i.e. residential, primary and secondary schools,

large pharmaceutical company buildings and prisons, are all examples of projects that

potentially have a large number of repetition. They should therefore potentially be

suitable for off-site production, including production in MFFs.

6.1.5 Quality

Off-site production and a factory environment are clearly beneficial for quality.

However, Gibb and Isack (2003) stated that some clients had experienced bad quality

from off-site construction. It indicates that off-site production does not automatically

give good quality; work is needed for it to be achieved. Quality is one of the main

drivers for off-site production and the Managing Director, as a person important for

strategic decisions, prioritized quality (and time) before cost benefits. Expectations on

the concept concerning quality improvements are guaranteed quality, control over

quality, reduced rework and mitigated risk of not fulfilling quality specifications. That

is consistent with Gibb and Isack’s (2003) findings of quality related benefits. Thus, if a

project requires a high and reliable quality it can be an essential reason and a basis for

decision to carry it out as a MFF project.

Standardization of the production process is in itself a way to increase quality

assurance. However, possibilities of having unskilled labour occur with successful

standardization and quality inspections then become essential. Examples are shown in

the Battersea project where faults can be linked to individual employees. By having

continuous inspections in the process, in addition to the final check, problems can be

detected in a timely manner. In the Battersea project, the quality check sheets are doing

this and there are further plans in implementing the ‘Tack and Track’ system. It will

ensure that quality inspections are performed continuous and can be a long-term

strategy for ensuring quality to the overall concept. Thus, it has been showed that the

Battersea project is working actively to achieve the goals of guaranteeing the quality. It

should reasonably result in a reduced risk of errors and rework, which in turn results

in more accurate delivery times and reduced costs.

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SWF also have an approach to achieve quality assurance, which is focused on climate

proofing the production. Eriksson (1995) explains that the factories dealt with concrete,

which can be damaged by having the wrong climatic conditions. However, there are

several building materials this applies to e.g. wood, insulation and gypsum. The ability

of the construction material to handle climate conditions might therefore be a

parameter when making decisions on producing off-site in a temporary factory.

6.1.6 Time and planning

Time is another main driver for off-site production. The Managing Director also

prioritized increased control over planning and time (together with quality) before cost

benefits for the MFF concept. Time becomes important particularly because the

consequences of not fulfilling contractual obligations can be costly. As stated by Gibb

(1999), off-site production can reduce the construction time and the same principles

also apply for a MFF project. It gives possibility for production to take place both on

and off site at the same time. It has been shown (with the Glenfrome project as an

example) that a reduced total construction time is an important advantage in the use of

the MFF concept. If a project has a limited or critical timescale, the time benefits can be

essential in the decision for using off-site techniques. Distinguishing the ways off-site

production in MFFs affect the time and planning aspects should contribute to sort out

how the MFF concept and off-site production in general, suit individual project

requirements.

Avoiding ‘working on top of each other’

In traditional construction, the time is especially critical close completion. Often several

trades should perform work within a tight schedule, resulting in working ‘on top of

each other’. Both the Managing Director and the Sustainability Manager emphasize off-

site production and MFF as a solution to ease an otherwise critical situation on site.

The most labour-intensive part of the project can make the most benefit through

production in MFFs. Battersea is an example of that, where the cupboards are a labour-

intense part and include operations from multiple trades.

Working parallel or in advance

Work traditionally performed one after the other, can in different extents instead be

performed in advance or parallel in the factory and on site. Examples of this are shown

by both MFF pilot projects. In Battersea, the cupboards are completed before the

groundwork on site is finished, which means production in advance. Glenfrome shows

an example of the possibility to build the wall panels at the same time as preparing the

expansion with demolition and foundation work. However, to work parallel or in

advance make a deviation from the traditional construction scheme, as the lead times

will increase.

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Reduced time waste in unnecessary movement

The Battersea project is a clear example of how movement of the employees is reduced,

in both moving between tasks and breaks as well as searching for equipment. When

thinking about the spread location of the apartments in the two buildings, it gives a

clear picture of the reduction in distances. All projects may not have the same clear

distance savings. However, a factory, stationary or temporary, will have an

environment that provides better conditions for organizing and standardizing, which

reduces waste of time in unnecessary movement.

Flexibility and timing to the on site construction

It is clear that MFF has an objective to guarantee delivery times. Since MFF is off-site

production, it will have the same advantage as other off-site strategies to give more

precise delivery times. As stated by Gibb and Isack (2003) and Venables et al. (2004),

the main benefits are improved control over the production times and less dependence

on weather. However, changed conditions on site are common and it has been

recognized that offering both precision and flexibility in time are important features for

the MFF concept. The basic idea is that the MFF projects should have a pull system

where the site 'pulls' orders that the temporary factory will respond to. However, the

Battersea project has shown that this can be difficult when handling projects with large

scale and high complexity. The change in delivery date together with other problems

has been solved by creating intermediate storage, counteracting a pull system.

A flexibility benefit factories have compared to traditional is that it can adjust the

speed by increasing or decreasing the workforce under more controlled conditions, by

for example introducing another work shift.

Less time spent on planning

Neale et al. (1993) states that off-site production provides possibilities to spend less

time on planning due to the repetitive work. However, that is more consistent for a

stationary than a temporary factory. MFF will be applied on projects and will not have

the same opportunity to reduce planning time and costs as a stationary factory.

However, if the time for planning instead is compared with the corresponding

traditional way of building, it should be less. This is due to the possibility to

standardize and organize the production work and thereby also the planning process.

6.1.7 Off-site production techniques and complexity

Possible off-site production techniques and competition

Fox and Cockerham (2000) have stated that there is a range of component

standardization when using off-site production techniques, from completely

standardized to almost completely customized. Table 3.1 shows further that the

components can be classified in level of prefabrication, from single components to

whole buildings. The literature therefore shows that there is a range of possible levels

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of production techniques when having the production off-site. The study has also

shown that the respondents believe that there is no limit to what the MFF concept can

be applied on. When looking at Table 3.1, it can be concluded that the wall panels in the

Glenfrome project count as non-volumetric units, while the cupboards fit the

description of the volumetric units. Furthermore, prisons and hospitals, both modular

buildings, have been exemplified as potential for use of MFF in the future due to their

high degree of standardization. This could possibly strengthen the view of MFF being

applicable on different techniques and building types.

Competition is however essential for the choice of techniques when using MFF. For

that reason, there has been some doubt to enter the market for modular buildings

where the competition is high, e.g. bathroom pods. Both the Managing Director and

the Sustainability Manager believe that in order to be competitive, they need to have

achieved a slick organization with a niche in offering flexibility regarding production

technique and location. A future competitive strategy has also been discussed with

advanced technique in 3D concrete printing. However, that is described as an extreme

of the level of technology for the MFF and is reserved for how the opportunities with

technology advances.

Complexity

Complexity is something that is mentioned recurrent in interviews. Both the Managing

Director and the Sustainability Manager clarify that complexity in itself does not have

to be a problem; complexity can be overcome by breaking it down. However, different

kinds of complexity need to be sorted out to get a picture of how it can complicate

application of MFF in the construction industry. The complexity that comes with the

chosen off-site production technique in a temporary factory can be separated into

complexity in variations and complexity in techniques. When the Sustainability

Manager indicates that Battersea and Glenfrome can be seen as two different extremes

on a scale of complexity, that can be seen as a combination of complexity in technique

and variations. Battersea has high complexity and Glenfrome has low complexity in

both.

Complexity in variations offered to client and strategy for standardization

The Sustainability Manager states that complexity in the offering of variations is an

issue for the MFF concept. In the Battersea project, a number of 4-5 different variations

from start may have seen reasonable. However, a change to 48 is a significant

difference that makes the production face new challenges in terms of supply, logistics

and work tasks. One of the problems observed in the start-up can be directly stated as

a variation issue. This is due to the variations of boilers and their positioning (left or

right), which complicate the drilling of the top board. The increased number of

variations and the traced issues to variations indicates that the factory could benefit

from an increased control over the changes in variations.

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The 18 different sizes of wall panels in the Glenfrome project correspond to 18

variations. However, how it varies only in size, cannot be considered as complex.

Variations will be something inevitable in many potential building projects. From

Jonson and Rudberg (2012) it can be concluded that there must be a balance between

offering enough variation to fulfil the clients needs without removing the possibility of

an efficient production. Venables et al. (2004) have emphasized that offering design

variations with a small variation in the production line is the best way of getting

economy. In accordance to that, variations should not be seen as an issue but can be an

issue in combination with complexity. Creating control over decisions and changes of

variations should instead be part of a strategy to meet the client’s needs. It must be

evaluated how consequences of committed variations should be handled in the

project´s early stage, but also how to handle the clients request or demand for changes

during production.

Barlow et al. (2003) shows strategies from the house building industry. Even if MFF

will not always be doing housing construction, it can be seen as a way to sort out a

strategy for standardization. The Battersea project can due to its temporary character

not directly be placed in the scale from pure standardization to pure customization.

Since the design is from the beginning based on the customer’s requirements and

design changes have concerned the whole design, it can be seen as a pure customized

project. At the same time, the standardized variations that in the beginning was

planned to be a low number of variations, shows a higher ambition for

standardization. This suggests that there is a lack of control and therefore, a clearer

strategy for dealing with the client’s requirements is needed. The goal will be to offer

adjustment to the client’s requirements but in a controlled way. It means that MFF

should strive to find a decoupling point. The work will be to separate the parts of the

design that the client can affect. In that way, be able to sort the supply chain to before

and after the adjustments for the client’s requirements. And the adjustments should be

in accordance to what the supply chain can manage and to achieve small variations in

the production line. The base should be the capacity of the supply chain and

production line in being responsive.

The potential markets in residential, primary and secondary schools, large

pharmaceutical company buildings and prisons all have high repetition and

possibilities for high standardization and low variation. Although, to ensure low

variation in the production line, the design process needs to be focused. The

importance of achieving a successful level of standardization and offered variations

also applies for other off-site production. However, for stationary factories, that is

something that only have to be dealt with once and thereafter there can continuously

work with finding the right level. For a MFF, it is crucial to find the right level of

standardization and offered variations quickly in the project’s initial phase. Otherwise

it can cause great difficulties that can hamper the entire project.

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Complexity in production technique

The study has showed that it is necessary to find production techniques that are

factory friendly to succeed with MFF as a concept. It means finding production

techniques that take advantage of the benefits of a factory environment and do not

have a high complexity. Complexity in production technique can be described as

complicated production steps or a large amount of steps, or a combination of these.

Although Glenfrome had some potential improvements, it was an already proven

method and had therefore no significant issues regarding the production technique.

The Battersea project uses materials normally used in traditional construction on site

(plasterboard, plywood, taping and jointing). These techniques include a high number

of steps and materials and bring the traditional disadvantages from these methods

such as waste, vulnerability, dust and difficult surface finish. The chosen techniques

are time consuming and causes bottlenecks.

The importance of finding the right production technique and level of complexity also

applies for other off-site production, as a wrong choice can cause problems. However,

stationary factories have other conditions to develop the production technique and can

work continuously with improvements. For a MFF project, the initial choice is crucial

since a poor choice can hamper the entire execution of the project.

From the Battersea project it is identified two ways to improve the production process

to avoid issues from a complex production technique:

1. Change production technique to one suitable for factory production

Neale et al. (1993) have confirmed that off-site production gives the possibility

to use and develop production techniques and methods different from

traditional construction. The plan of changing the plywood-plasterboard

construction to ‘new’ materials is an example of this. That would reduce the

problems with customized boards, storage, waste, handling (weight) and dust.

2. Outsourcing

Outsourcing parts of the production process is a way to reduce and avoid tasks

that are too complex for the company. These parts can be made less complex by

breaking them down to smaller sub-assemblies and choosing appropriate

suppliers for each of them. Battersea has two examples of this. The first

example is trying to find a supplier that makes the fitting of plastic cover strips

to reduce a time-consuming work task in the production.

As Neale et al. (1993) have stated, when producing off-site, there are two design

approaches, which provide different prerequisites for the complexity in technique. The

first is to use simple traditional production techniques and move the production from

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the construction site to a factory. However, the design of the cupboards in the Battersea

project cannot be seen as simple production techniques. It has a lot of steps, which are

not considered to be factory friendly. The second design approach presented by Neale

et al. (1993) is to develop specialized methods to do specific modules. That is in line

with what can be achieved with the potentially new materials that are being

investigated. The design in Battersea was from the start not aligned with any of the

described design approaches. What has been done in the Battersea project is more

aligned with what Pasquire and Connolly (2002) describe how not to do the design:

carving out a piece of the building and with the same production technique produce in

a factory. That is not to take advantage of the benefits of producing in a factory and the

Battersea project has due to the complexity encountered problems. This strengthens the

need to have an approach in line with those described by Neale et al. (1993).

Techniques that are factory-friendly and can make use of the benefits from producing

in a factory can easier be found with a consistent design approach.

6.1.8 Factory investments and equipment

When it comes to the factory building, there seem to be different options to choose

from for a MFF project. The study has shown that temporary factories ranges from tent

on or near the building site (e.g. Swedish field workshops) to scalable modular

containers (e.g. Flexible Field Factory) with a range of options in between. When

studying the choices of the concepts SFW, FF, MFF and FFF, it appears as if the

demands on the factory building increases with increasing complexity in production

technique and willingness to make investments. It can be concluded that SFW and FF

has a strategy that involves rather simple buildings and minimal capital investment.

FFF on the other hand, uses a mobile container-based solution and has a strategy of

investing in advanced technology. By the pilot projects, it seems as if MFF has a

strategy in between these concepts. The demand on the building and level of

investment varies depending on the scale and complexity of the project. However,

what seems to be important for all the concepts is that the factory either is mobile or

used temporarily, on or close to the construction site.

A mobile container based solution could be a possible future also for MFF. Besides FFF,

MM is another example of a concept that advocates a mobile solution. Although MM is

a concept for the manufacturing industry, it has a lot of similarity with the FFF. This

applies in particular, but not limited to, their pursuit of a flexible and mobile

production solution through automated processes. What can be concluded from both

concepts is that they promote a container-based solution as having a simple and rapid

transportation with shorter setup and closedown phases. As discussed previously, a

shortened start-up and closedown would mean that the MFF concept can be applied on

smaller projects as it will decrease the non-value added time. This therefore means that

a container-based solution for its production would favour the concept. However, if

making investments, the expenditures need to be covered by assured work orders,

which can reduce the concept’s flexibility in time. A container-based production also

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requires that the production can be accommodated within the container, reducing the

flexibility in production techniques. As an example, that would not have been possible

in the Battersea project due to its scale with much work in progress. Making use of a

container as a factory building can therefore restrict the application of the concept to

projects with small products or with less work in progress. As the Site Manager

argued, the choice should be done from the project's individual needs. However, the

investment level also needs to be weighed against the strategy.

The level of equipment seems to be able to vary with the complexity in the production

technique and willingness to make investments, similar to the demands on the factory

building. The MFF pilot projects have not used more advanced equipment than would

be used on site. It confirms that it for MFF is fundamental to keep investment costs

low.

Since 3d-concrete printing is mentioned as an extreme of a scale of technology,

automation can be considered as a potential future for MFF. The benefits that Martinez

et al. (2008) claim to be a result of an increased implementation of automation, namely,

increased quality, productivity, safety and control as well as reduced labour costs, is

such that the MFF would benefit from. This has attracted the attention of decision

makers for the FF concept, which (at the time of writing) explores the possibility of

automating the production process. Although, it must be kept in mind that automated

production systems have been found to have an increased sensitivity to disturbances.

In less complex concepts such as FFs, which is limited to only use one type of

production technique, this could be acceptable. As Stillström and Jackson (2007) have

stated, the number of variants can make it too complex and expensive for automation.

For MFF, which must handle more complex production systems, this extra sensitivity

can therefore pose a greater risk. The question also arises about which types of

technologies or processes that should be automated? It would be impossible to

automate the production for all types of construction projects MFF may handle. It

seems therefore that the concept can choose to go in two different strategic directions.

In the first, it can keep having a focus on low investment costs by hiring (as in SFWs) or

buying few and inexpensive tools and equipment. This would then be in line with the

desired flexibility. However, if it should turn out that there is a market with the right

conditions and a continuous demand, there is nothing to say that it is not possible to

invest in automation. Nonetheless, it must be borne in mind that the reduction in

flexibility means a risk as the objective with the ability to apply different off-site

techniques can be waived.

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6.2 Organizational prerequisite

6.2.1 Contracting and project organisation

The way the MFF concept can deliver a project seem to be able to vary. In the

Glenfrome and Battersea projects, MFF has been performed as suppliers of off-site

production techniques to being a main contractor. Future projects for applying the

MFF concept should therefore theoretically be able to perform in either way. Early

decision on the use of off-site production techniques appears to give the best

conditions for a successful off-site implementation (Gibb & Isack, 2003; Goodier &

Gibb, 2007; Pan et al., 2008), which also applies for MFF. The recognized constrains

from procurement (Blismas et al., 2012) applies also for MFF; early key decisions,

understanding of value from producing off-site and early involvement of expertise.

This would be simplified by having off-site in the specification and that the off-site

construction is led by the client (Pasquire & Connolly, 2012). In MFFs and Skanska’s

case, that would mean being the main contractor and have control over early

involvement and early decisions, thus overcoming the procurement constrains. The

Site Manager also supports the argument, that being a main contractor gives better

potential for success.

It has been identified that design-build, partnering, ECI (Early Contractor

Involvement) and NEC (New Engineering Contract) are all contract types used in

traditional construction which is believed to also be suitable for MFF. All of these

contracts are examples of a more open approach between the project participants and

where the contractor gets a bigger responsibility. Also, Koskela et al. (2002) states that it

is important that all project participants collaborate if the value is to be increased and

flow is to be created in the process. Standard building contracts that discourage

cooperation should therefore be excluded from use within the concept.

Regarding organisation, the intention is to have a group with management,

engineering and factory skills to support the start-up phase. They will be responsible

for training locally hired employees to run and operate the factory. This is very similar

to what Baloff (1970), Harrison (1981) and Almgren (1999) describes as an operational

and technical start-up group that supports the technical learning and eases the

information handling in projects. In Battersea, a group that goes in line with their

description has been identified although there is potential for improvements by clearly

distinguishing it.

From the observations, it is noted that the site manager alone has the main

responsibility for the production in the project. The site manager therefore has great

knowledge about the production process and experience of a start-up. Since the

employment is directly for the project instead of within the research project, there is a

risk that knowledge is lost which could have strengthened the concept. Having a

distinct start-up group with clear guidelines for their work and use would reduce the

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risk of having most of the knowledge tied to one person. That would be a way to

secure feedback of the experience within the company. There is a possibility of having

such a group as support throughout the whole production process. However, the need

for additional operational and technical functions has foremost been identified as

important in the early stage of production.

6.2.2 Coordination of the organization

It has been shown that off-site strategies require early decisions when it comes to

matters that affect production. Höök and Stehn (2005), also pointed out the importance

of early decisions since the longer lead-time makes it difficult to make design changes

later in the process. Problems can arise when the approach of early decisions is not

familiar. That has been shown in the Battersea project where the utility cupboard is an

example of a product with a high degree of completion, longer lead-time than

traditional and many problems derived to late decisions. The Lean Consultant and Site

Manager argue that the lack of early design decisions has caused the greatest

production problems in the project. The Managing Director therefore considers that

early contractual involvement is an important part of the concept. To guide

participants toward earlier decisions is thus a coordination task that the MFF

contractor needs to handle.

The Battersea project can also exemplify where multiple stakeholders have caused

design problems. That is because they all have wanted to impact the design. Further,

the Site Manager refers that large enterprises with many hierarchical levels can have a

tendency to hamper the implementation of a project by obstructing the decision-

making. This makes sense since longer decision chains should require more control in

coordination. As Gibb (1994) points out, the main contractors are responsible for

managing the interaction between the involved subcontractors and ensure that

everyone is collaborating and pulling in the same direction. In the Battersea project, the

main contractor manages this role and their coordination ability affects Skanska. This

illustrates a case in which the MFF is in a dependent position relying on the main

contractor to have a successful coordination. Since early involvement is important for

the concept, it is also important to know what risks are taken compared to having the

main contract. Being dependent on another actor is therefore something that should be

avoided.

6.2.3 Management information technology

ICT and RFID tools identified in a MFF context are BIM and the Tag and Track system,

these can be seen as management information technology which potentially will be

included in future MFF projects. Predicted benefits from BIM and RFID are for

example; guide construction team, easier to involve suppliers, facilitate materials

tracking to ease site logistics. Also the Managing Director argues that BIM is important

for future production off-site. However, in the pilot projects, these are identified

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ambitions rather than actions. In the Glenfrome project, it could be found that the

implementation was hindered because the BIM-model had insufficient quality

regarding level of detail. What caused this cannot be determined, possibly due to lack

of engagement or knowledge, aligned with what is stated by Voked & Brennan (2013).

However, it is clear that benefits that information technology possibly can bring should

benefit MFF. Therefore it should, when suitable, be integrated in the process, which is

made easier with the right knowledge among the involved.

6.2.4 Design process

That off-site production sets other demands on the project participants applies

primarily to the designers. As Neale et al. (1993) argue, off-site production, and so MFF

as well, also sets other demands on the designer's technical knowledge. Gibbs and

Isack (2003) have found that inappropriate design is one of the reasons when off-site

production does not meet its expectations. The design therefore has to suit the

production system and the interfaces between constructions on and off-site must be

clearly thought through so that it does not cause later problems. In the Battersea case,

this was shown in a design only allowing 1/3rd of the cupboards to be produced off-

site.

From the study, it seems that Glenfrome did not have any design issues whilst the

Battersea project had several. The reason is that in Glenfrome, ModCell’s proven

building system was used, in which the design has evolved over time through

experience. In Battersea, both the product and the technology were new and as the Site

Manager notes, it meant a great challenge. It is uncertain whether the project's

designers had previous experience. In any case, as have been stated previously, the

design has not been adapted to factory production but has relied on traditional

methods of production. This can thus be considered as an example of an inappropriate

design when using off-site production techniques. Earlier involvement in the design

decisions would enable to build in manufacturing principles into the product to avoid

the unnecessary problems and expenses. According to Neale et al. (1993), early

involvement can make the design process more productive, which is by Goodier and

Gibb (2007) stated to result in a shortened lead-time and reduction in costs. As Höök

and Stehn (2005) have stated, it is then about staying loyal to the design. It can be

tempting to make changes during production. However, these changes mean

disruptions in the learning and as Baloff (1970) has stated, one has to bear in mind that

those changes can have a major impact on the long-term production efficiency. The

obvious problems in standstills and unmanageable material supply in the Battersea

project is examples of that. They have been caused by changes and delayed decisions,

and therefore illustrate the importance both for early decision-making and having

loyalty to the design. As such, the lack of designfreeze can be seen as a source for

problems in the Battersea project. As the Managing Director emphasizes, there has to

be an increased discipline regarding design and design changes. The lack of it makes it

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hard to achieve a stable and standardized production. In the Battersea case, it is based

on that the concept is acting in a traditional construction environment with risk

management mentality that Pasquire & Connolly (2002) describes as ‘fire fighting’. The

mentality of the project management needs therefore to be changed into one that

emphasizes mistake proofing. For MFF to go further, it is of utmost importance to

make sure that the focus is on achieving a more controlled design process through

increased discipline over decisions and changes.

Additionally, a need for MFF to handle flexibility in design is also identified. There

will always be a challenge to be able to offer and handle flexibility in the design during

production. It will also always be a risk that the initial design can not be the final.

Forcing early decisions and early design freezes means that there is a risk that

decisions and alternatives are not as well developed and explored as they could be if

given more time. The most important thing is to find a strategy to get trouble-free

designs. Koskela et al. (2002) states that Lean Design can be a solution, with decisions

made at the last responsible moment. It is possible by having control over lead times

throughout the production chain. For MFF, making decisions in the last responsible

moment gives more time for careful consideration of the design and alternatives,

which would result in a reduced need of making changes. It would also make the

concept able to offer the client more time and therefore possibly more options to

choose from. A strategy for such decision making processes would imply that the MFF

concept could better balance the need for flexibility from traditional construction

projects against the need for stability that factory production demands. Thus, what is

meant with early decisions should be decisions made in the last responsible moment.

As Koskela et al. (2002) suggest, the critical timing of these decisions should be clarified

by backwards planning, taking into account the lead-times for different choices.

Decisions or changes after the last responsible moment must not be accepted.

6.2.5 Supply chain

The observations have shown that cooperation have taken place between Skanska and

the suppliers of board materials in the Battersea project. The suppliers of the current

plastic- and plywood system have for example met the requests of pre-cutting the

boards and pre-drilling the holes in the top part. If it were not for erroneous

measurement, it would have saved both material and time. As reported, there are also

on-going discussions with additional suppliers of board material to possibly replace

the current design towards a more factory friendly for future similar projects. Even so,

the current delivery system as a whole in the Battersea project, is considered to be

ineffective due to having too much of a push character. This shows that it is of

important to have collaboration both regarding technical solutions but also for a

smooth flow in terms of delivery. The Managing Director and the research funding

application states that a shorter respectively an improved supply chain efficiency are

part of the keys to the MFF concept's objective. By achieving this, it would make the

concept more responsive by supporting the strive for decisions to be taken in the last

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responsible moment. As such, it allows for decisions to be made in later stages, which

increases the flexibility in design and production that the concept can offer.

Involving suppliers in the early planning can according to Goodier and Gibb (2007) be

central for choosing the right off-site production technique. However, it ought also

lead to better understanding of the project’s requirements, increasing the possibility for

a better collaboration.

6.2.6 Labour and skills

What appears to be important in the MFF concept is the use of multi-skilled labour. For

example, the Sustainability Manager claims that to avoid bottlenecks, slick material

and waste and have a workforce that are multi-skilled, instead of specifically skilled,

are ways to lean the concept. Venables et al. (2004) have shown that this is important

for off-site manufacturers in general. Multi-skilled labours should be able to create

flexibility in the workforce, where a few individuals are capable of handling many

different tasks. The Battersea project is an example. They are relying on some multi-

skilled labour because of the complexity of the production process. Furthermore, it

seems realistic that using multi-skilled labour will, in addition to reducing costs, also

contribute to avoidance of different trades working on top of each other.

Off-site production can be seen as a solution for the lack of skills in the UK

construction industry (Venables et al., 2004; Goodier & Gibb, 2007). Even if a lower skill

level can be recognized as a driver (Goodier & Gibb, 2007), it is not entirely evident

whether off-site benefits from a lower skill level. Aligned with Goodier and Gibb’s

(2007) findings, it depends on the conditions for the individual off-site production

project. Also Argote and Epple (1990), the Managing Director, Sustainability Manager

and Lean Consultant emphasizes that reduced skill requirements results from a

successful standardized process, thus not necessarily just by building off-site. Further,

the Lean Consultant highlights the possibility to have different kind of skills in the

concept and that the work should be planned according to optimal use of their

respectively skill level. This is also confirmed by Neale et al. (1993), as it can create

conditions for unskilled labour to learn limited parts of specifically skilled tasks. The

possibility to utilize unskilled labour should as such be considered as an advantage

that comes with the use of the concept. However, the Glenfrome project has shown that

use of medium skilled labour can instead benefit the concept. Although the production

process of this project was very simple, the low level of knowledge (by the apprentices)

reduced the project’s productivity.

FF on the other hand, has managed to create a process where employment of only

unskilled labour is possible because of a successful standardization. However, the

Managing Director and the TSB funding application have stated that innovation is

central and beneficial for MFF. Clarke (2002) has also confirmed that it is important for

factories producing off-site in general and emphasizes that without the right training

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and skills, innovation as well as productivity is restricted. Depending on the goals and

expectations of innovation with the temporary factory, it should be taken into account

that a production process with unskilled labour can hamper innovation. Contrary, an

increased overall skill level should favour innovation. A medium skilled workforce

would balance this.

As a summary, finding the right labour is crucial according to Baloff (1970), which is in

accordance with a discussion about which skill level the labour should have.

6.3 Difficulties in start-up and operation

As presented in Table 5.3, a number of problems due to changes were noted during

observations at the factory for the Battersea project. To get a picture of the causes of

this changes, Table 5.3 has been supplemented by two columns and is presented in

Appendix B. The first column indicates the origin of the problem and the second

indicates if the problem is considered to be linked to the choice of production off-site

instead of on site.

When looking att the matrix, it can be stated that most of the problems are attributable

to the design stage, while problems from the production stage is the second most

common source. All problems have affected the production but they can be classified

into two types of categories depending on how the impact occurred. The first involves

conscious design changes, to which problem number 7 and 9 belongs, i.e. changes

around the cupboard’s appearance and performance. Although this category had only

two problems during the observations, their consequences were severe as they meant

congestion in the factory. The remaining problems exemplify the second type of

change, which are those made because of errors. It can be concluded that both

categories is due to lack of knowledge about the production system requirements. By

separating them from one another, it is easier to create strategies to prevent future

occurrence of similar problems.

The first category, conscious design changes, involves behaviours while changes due to

errors are results of mistakes. Problems based on mistakes require a different strategy

and should be handled through increased reviews. The first category (conscious

changes) needs a strategy that can break old patterns, which implies a different kind of

challenge. Its problems can be traced to off-site techniques implying longer lead-time.

This is in agreement with what was found earlier; the concept requires a decision

timing in line with last responsible moment and an increased discipline over the

design decisions. When it comes to the mistakes that has been made, it can be

distinguished from the matrix that eight of these 15 problems is due to that production

takes place off-site instead of in a traditional way. Further, the problems can be linked

both to the design and production phase. As Vokes and Brennan (2013) have stated,

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off-site production puts other demands on the project professionals. The mistakes that

have been made may therefore indicate that the project participants do not have

enough experience or knowledge about how off-site production should be managed. It

is important to understand that the errors that arise from this not only affect the

production at that moment. According to the Baloff (1970), they can cause disruptions,

which can also lead to impaired learning ability throughout the lifecycle of the

production process. As suggested by Almgren (2000), mistakes should be prevented

through consistent quality assurance where time is spent on ensuring proper functions.

That should be done both during product development and production.

All changes that has been done in the project belongs to what Ballof (1970) categorizes

as changes in product design and production factors. As they have caused disruptions,

it has been difficult to achieve a stable and standardized process within the project.

Ballof (1970) states that this error category is one of the most common in the start-up.

This shows that making classical start-up mistakes is possible also with temporary

factories. Since the concept has a project nature by being temporary, it will always be

facing start-up phases which means that it is a part of the concept that must get

attention. The extent and difficulties from start-up can not outweigh the operation and

advantages that MFF have. Although it can not be stated if that is the case in

Battsersea, it can be stated that the extent of the learning period and therefore the start-

up was underestimated. In this case, it seems like the budget will weigh up for this so

that the project can still show success. However, it indicates that the extent of the start-

up is difficult to control and hard to assess in advance. In line with Ballof’s (1970) and

Almgren’s (2000) arguments, the concept should therefore work with a plan to achieve

control over the start-up phase, much in line with the MFF's tool kit. As with the

planning of the design decisions, all project participants should also take part in this in

order to achieve a good result.

In total of what has been found so far, it implies that many of the decisions and

fundamental work will be moved to an early stage when applying the MFF concept. To

strengthen what has previously been suggested, this may be yet another reason to

implement an operational and technical start-up group. Since the start-up phase will be

continuously recurring within the concept, the need for such a group will be constant.

The necessity for a start-up group therefore becomes even more motivated.

6.4 Principles from manufacturing

From the interviews has been established that the MFF concept is largely influenced by

the manufacturing industry and that the concept strive to work with the benefits that

manufacturing can bring. Limitations of the improvements in lean and design have

been identified in that the lean consultants came in late in the project. The Lean

Consultant has confirmed this and it applies to both the Battersea and Glenfrome

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project. In the Battersea project, potential seems to have existed for the lean consultants

to improve the design of the cupboards. While in the Glenfrome project, much of the

improvements were connected to the layout of the production system.

6.4.1 Lean

Although Eroglu & Hofer (2011) identified that a lean philosophy does not favour all

industries and companies, nothing has been found that indicates that MFF would not

be favoured from lean philosophies. It is noted that Lean production principles have

been applied to FF, MFF and FFF, which shows that it is an important part in a concept

of temporary factories. In the Battersea project, attempts to lean the process have been

identified in accordance with 'The House of lean production', see Figure 3.5. Each block

has methods that in different extents are useful and applicable on the Battersea project;

Stable and standardized processes and continuous improvements

Standardized work and visualisation can clearly be identified in some extent, but

expressed visions for 3D-instructions and unskilled labour reveals higher ambitions for

standardization in this project. The work for a stable and standardized process can in

the Battersea project strongly be connected with the built in quality and continuous

improvements. These types of standardization improvements have been developed

gradually and examples are; templates for mounting of components, reduction in the

number of variations on bolts and nuts, visualization of delivery dates and labelling

shelves for material storage. Additional work classified as continuous improvements

are reduction of waste by having the boards delivered in correct sizes, simplifying the

cutting of plastic cover strips for the electrical distribution board and looking at

possibilities for easier construction methods such as having complete units come in

flat-packages.

Several of these improvements can be considered as built in quality in the design,

which helps to reduce errors. Another way to have control over errors is the use of

quality control sheets. These still have potential to be more efficient by being

performed on a more regular basis. For that, it must have as user-friendly methods as

possible, in line with the proposed Tag and Track system.

JIT

When it comes to the fourth pillar, Just-In-Time/levelled production, creating flow with

lean principles has been hampered mainly in three ways;

Stop in the production flow for two main reasons; delays on site as well as

design changes/late decisions have postponed completion/delivery

(intermediate storage as a solution)

Limited work floor layout efficiency. Workers have to move to the modules,

instead of the other way around, due to difficulty in moving the cupboards.

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Difficulties to achieve a flow with takt. The main reason is that several tasks

benefit from being carried out in different batch sizes.

Stop in the production flow has had a great impact on the production process as it has

resulted in insufficient space in the factory. The two main reasons for this should be

included in risk assessments since they are both issues that can be considered common

in the construction industry. Delays on site or changes in delivery have to be

considered as a risk and assessment should include possible intermediate storage.

Moving the cupboards within the factory was considered but excluded. It was

considered too difficult to find a way of moving them smoothly and that the space was

not sufficient. The other problems mentioned above contributed to a gathering of

additional cupboards and lesser space available, making it even less feasible to move

them. However, a technique to move the cupboards smoothly could give a more

efficient layout. It would contribute to improvements in reduced movements and

transports, facilitate production pace and customize the working stations for a greater

efficiency.

To manage the production with takt has not been possible in the Battersea project with

the techniques used. Techniques that are not dependent on a specific batch size allow

control and contribute to achieving a smooth flow and a pull system.

Involvement

The Battersea project is also a good example of how to work with involvement. When

employing labour, it has been considered important to select individuals with

multifunctional skills and an ability to work in teams. Taking advantage of the

employee creativity has contributed to improvements in the production process. Both

the Managing Director and the Site Manager seem satisfied with the level of innovation

and the teamwork achieved in the process.

Involving the workers in the planning of tasks is considered important also by

Harrison (1981) and Reis (1991).

A stable and standardized process is fundamental for all the other lean methods in the

‘House of lean construction’. It can be identified that the difficulty to get the potential

of lean methods can be due to the process having fundamental weaknesses in stability

and standardization. This should be a priority in order to achieve a foundation to

implementation of the other lean methods in the House of lean production.

Jidoka

This is a method that should be applicable on MFF projects. However, it is difficult to

implement before steady state is reached, which is the case in the Battersea project.

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Had it been applied with the many problems that the projects had, the production

process would had continuous standstills.

6.4.2 DFMA

Boothroyd (1994) and Bogue (2012) describe that problems occurs in the manufacturing

industry when the product design is passed on from the designer to the manufacturer.

Several of such, design related problems, have been identified in Battersea (see Table

5.3). A reason when the design is not optimized is by Bouge (2012) stated to be when

designers have a lack of knowledge and stick to methods they are familiar with. That

can be considered being the case in Battersea where traditional construction methods

are used, not considered suitable for a factory environment. As Boothroyd (1994)

argues, should DFMA offer to improve early teamwork between disciplines and

specific analysis tools. Which could be important for MFF to be able to get a more

optimized design and reduce the design related problems. It is observed that all

respondents pointed out the importance of considering the factory friendliness or

manufacturability during the design process when applying the MFF concept.

Although all respondents did not name DFMA, this method is an example of a solution

of what seeks to be achieved. The fact that FF and FFF also both have applied DFMA

principles in their product developing processes shows that the method should be

suitable and beneficial also for MFF. It also confirms that the method can be used for

different types of products, which has been stated by Boothroyd (1994) and Edwards

(2002). That is important, as it has been concluded that the concept of temporary

factories must be able to handle different techniques for doing different kind of

products.

By Boothroyd (1994) it has been understood that the benefits that come with using

DFMA are minimized production costs, shortened lead-time for product development

and manufacturing as well as making the product reach the market more quickly.

There is nothing to suggest that the benefits would not be applicable also on MFF,

resulting in lower production costs and reduced production time. It therefore indicates

that DFMA should be part of the MFF concept.

When it comes to unskilled labour, both the Managing Director and the Sustainability

Manager have pointed out the importance of manufacturability as a way to make it

'failproof'. Since DFMA strive for simpler processes, Bogue (2012) states that it is an

important method when having a high level of low skilled labour. As such, the

opposite can also be stated as true, which is that DFMA allows for a greater use of

unskilled or lower skilled labour. Further, Boothroyd (1994) highlights that the

simplification that is an outcome of DFMA can result in the product being too simple

to justify an automated process. When considering going in the strategic direction of

implementing automation, it is noteworthy that DFMA may be able to compete in

efficiency. The method is more in line with the MFF concept and allows efficiency

without involving fixed costs, which can thereby retain the concept’s flexibility.

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6.5 Challenges and barriers in general

To create a strategy for the MFF concept's continued development, the challenges

mentioned during the interviews regarding MFF has been summarized and classified

according to a common denominator, see Table 6.5. It appears that the challenges that

have been identified are related to change in mentality, suitability for factory

production, basis for decision-making, creating competitiveness and that the concept

needs to show potential.

Table 6.5 Summary and classification of the challenges that the MFF concept is

facing.

Challenge Category

Project participants are "builders" and not manufacturers Change in mentality Meeting the traditional construction mentality with late

decisions

Making the design suitable for factory production

Suitability for factory production

Realizing the importance of DFMA

Making the project factory-friendly in terms of suppliers and transport

Implementing methods and technologies (DFM, BIM and RFID) for development and competitiveness

Finding the right projects Basis for decision-

making Come up with the basis for decision-making

Identifying where else MFF is suitable

Making a commercial offering

Creating competitiveness

Get the concept more competitive than other options

Keeping up with new technologies to be competitive

Making continuous development to be competitive

Viability needs to be proven

Concept needs to show potential

Project team wants to see full potential for deciding to go forward further

The MFF concept needs to show success by showing control over cost, time and quality rather profitability, so people want to build from that

As it has been explored in the previous sections, the first two categories are about

creating stable and streamlined processes that have control over the finance, time and

quality. As such, these are challenges directly associated with the projects execution.

When they are overcome, it will create processes that have control of finances, time

and quality. The change in mentality has been shown to be dependent on greater

discipline in project management regarding design and design changes. When this

discipline is increased, it will contribute to earlier involvement in planning the project

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and decisions made with right timing. Adapting the production process to a factory

environment in terms of design processes, suppliers and logistics management will

increase the efficiency of the actual production.

As more projects are carried out within the MFF concept, more data will be available

for the company. There is then more basis for assessing the appropriateness of using

the MFF concept on specific projects. Thus, it is possible to identify the projects that

best benefit the concept and the company. Depending on how slim the production

processes can be made, different strategically markets can be chosen. One option may

be to go into markets with high potential but with high competition or to specialize in

smaller markets with less competition as the Sustainability Manager suggested.

Whatever the choice, the concept will increase its competitiveness by achieving an

efficient production that can guarantee delivery times and quality. However, the basis

for evaluating the concept’s competiveness must be done after it has had a chance to

prove its potential. Further, the potential will not be allowed to be shown until the

correct decision basis has been developed and stable production processes have been

achieved. As such, it shows that the last two categories of challenges are directly

dependent on the first three; change in mentality, suitability for factory production and

a basis for decision-making. The strategically work for developing the concept should

therefore first and foremost focus on these three.

6.6 Decision basis for application

As the MFF concept is novel, it has limited access to calculated basis for decisions and

no distinctive limitations in possible application. It has been stated that MFF has a

challenge in finding the right projects for continued implementation. MFF needs

methods for decision-making, in agreement with the identified need for off-site

production in general (Gibb & Isack, 2001,2003; Goodier & Gibb, 2007; Olsen &

Ralston, 2013). It is confirmed by the research project’s on-going plan to develop a

decision-making matrix based on lessons learned. A matrix could work as an initial

assessment of applicability. Since the organisation and contractual constellation may

look different, it could potentially be used by a main contractor, or by a contractor

presenting MFF ideas for a client.

It can be seen that there is a wide range of possible applications of MFF, even though

the concept clearly has limitations. Ultimately, an application has to add an overall

value to the main construction project. To be implemented successfully, it needs to be a

balance between adding that overall value and the barriers in disadvantages and

limitations that the concept brings. This balance will look different for the individual

MFF projects. Since the concept is novel and includes start-ups that are difficult to

predict, there are reduced chances of having estimates as a basis for decisions.

Therefore, the focus should be on finding strategic keys to evaluate the applicability of

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MFF on individual projects. Figure 6.6 presents a suggested way of looking at criteria in

benefits and barriers to assess the applicability of MFF.

Figure 6.6 Assessments that should be made for deciding on application of MFF on a

project.

6.6.1 Benefits

MFF is an off-site strategy and shares many decision basis criteria with other off-site

strategies. Thus, it is suggested a list of off-site benefits that applies also for MFF, for an

initial determination whether off-site production can be applicable. It can be done by

considering how the off-site advantages apply on the construction project, compared to

traditional construction. This has been identified from the studies of Neale et al. (1993),

Goodier and Gibb (2007) and Gibb and Isack (2003) and is consistent with what can be

identified also for MFF. Thus the benefits listed in the first column in Table 6.6a applies

for off-site production in general as well as for the MFF concept.

How MFF specific advantages can apply on the project should also be assessed. MFF

specific benefits in comparison to other off-site production (in stationary factories) that

has been identified as essential are all different types of flexibility, presented in column

two in Table 6.6a.

Decision

basis

1. Offsite vs traditional,

Off-site production beneficial?

2. MFF vs stationary

factory,

MFF beneficial?

3. Off-site production barriers?

4. MFF barriers?

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Table 6.6a Benefits for MFF, generally for off-site production and MFF specific.

Benefits

1. Off-site production beneficial?

2. MFF beneficial?

Control over quality

Conditions for using efficient

processes and production techniques

Avoiding ‘working on top of each

other’

Working parallel or in advance

Flexibility and timing to the on site

construction

Less time spent on planning

Climate proofing

Health and safety benefits

Flexible in project scale and duration

Flexible in location

Flexible in production

technique

6.6.2 Barriers

Also, it has to be considered whether the limitations that off-site implies will be

outweighed by the benefits. The barriers identified for off-site production, which also

applies for MFF, are listed in first column in Table 6.6b. They are based on criteria from

Neale et al. (1993), which is in agreement with criteria emphasized in interviews.

Lastly, it is crucial to assess the MFF specific barriers against the benefits. MFF specific

barriers identified as crucial for application are listed in Table 6.6b, which are all

founded in low capital investments and difficulties to achieve an efficient start-up. In

summary, MFF becomes hard to apply if the start-up is too difficult and extensive.

Therefore, the MFF specific criteria’s have been identified as fundamental through

their impact on the start-up phase. Amount of competition however, is not directly

linked to this but is an overall strategic consideration that must be made to ensure

enough efficiency in a MFF project.

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Table 6.6b Barriers for MFF, generally for off-site production and MFF specific.

Barriers

3. Off-site production barriers?

4. MFF barriers?

Insufficient number of repetitions

Long lead-time

Requirements for interactions to

the rest of the building

Lack of accessibility on-site

Transports and handling of large

objects

Complexity in offered variations

Complexity in production

technique

Limited investments in factory

building and equipment

Difficulties to achieve a

disciplined design process

Difficulties to achieve early

involvement

Competition

100

7 CONCLUSIONS

7.1 Propositional description

R1: How can the MFF concept be described?

Central to this research, it has been concluded that the MFF concept is an off-site

production strategy or a method in the context of MMC. However, MFF is

distinguished from the conventional way of producing off-site by having temporary

factories on or close to the construction site. The geographical location is dependent on

what is being produced, scale, factory floor area, delivery programme and labour costs,

rather than transportation cost. The concept should have a standardized process of

start-up, operate and close down a factory, which is carried out in projects. By being

temporary, it allows for flexibility in location, time and technique. These factors are

central for the concept’s competitiveness against stationary off-site factories by making

the concept more responsive to the market demand. Having a low capital cost appears

in the concept’s current state to be an important strategy for achieving this. By not

having a stationary factory and fixed costs, the three factors of flexibility are met by:

being where the market needs are and having short transportations and supply

chains,

being able to start and close in pace with the market demand and

being able to use different off-site techniques.

Proposition 1:

The MFF concept is an off-site production strategy that on projects intends

to apply a standardized process for start-up, operation and close down of

temporary factories on or close to the construction site.

Proposition 2:

The MFF concept’s competiveness against stationary factories is based on

having a strategy with low capital investments, allowing flexibility in

location, time and technique.

This study further identified that the objectives of the concept are ensuring delivery time and

quality, saving costs as well as being able to apply different production techniques for the

main project. The MFF concept has the first three objectives in common with other off-site

production strategies and the factory environment makes them easier to achieve. The

difference is that the MFF concept must find ways to rapidly make use if that benefit. As the

concept is about a factory process applied to projects, it has limited possibilities to achieve

the same benefits that a stationary factory have through continuous processes. These are

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are long-term relationships, being able to work with continuous improvements and investing

in equipment for increased efficiency.

Proposition 3: The objectives of the MFF concept are ensuring delivery time and quality,

saving costs and being able to ally different techniques for the main

project.

Proposition 4: The MFF concept’s projects have by being temporary, limited possibilities

to achieve the same benefits that stationary factories have from

continuous processes.

In the concept’s current state, there are no possibilities to make conclusions about specific

scales, techniques and contract types that are applicable for the MFF concept. There seems to

be a possibility to apply the concept both as main and as a subcontractor as well as use

different off-site techniques on projects with varying scales. However, each individual

project needs to be assessed on its own prerequisites.

Possible factory buildings and investment in equipment can be various and seem to vary

depending on the scale and complexity of the project. Examples of buildings are tents,

farmers’ barns, rentable units and mobile containers. The equipment should be kept simple

as the basic principle is to keep the investment cost low to maintain the concept's flexibility.

Proposition 5: The level of investment in factory building and equipment should be kept

low to maintain the MFF concept’s flexibility.

In the execution on MFF projects, the intention is to employ local labour for the different

located projects. The labour should preferably be multi-skilled which contributes to

flexibility in the workforce. To support the technical learning and ease information handling

in the start-up phase, a start-up group will complement the production team. The group

consists of an operational and technical organization having management, engineering and

factory skills.

Proposition 6: The organization in a MFF project should in the production preferably

consist of local employees, medium and multi-skilled labour and a

technical and organizational start-up group to support them.

It seems that increased automation is a possibility for MFF as it contributes to increased

control over quality, productivity, safety and reduced costs for labour. However, it will give

other strategic prerequisites for the concept since it requires investments and can increase the

sensitivity for disturbances. That will reduce the concepts overall flexibility in technique and

market fluctuations, which are essential for the strategic direction of low capital cost. If MFF

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takes the direction of automation, containers are a possible solution to constitute a factory

building. It will facilitate the transportation of equipment and allow for a quick start-up and

close down phase.

Proposition 7: The MFF concept has two possible strategic directions: to keep the

investment cost low which maintains the concept’s flexibility or to

automate the production for an increased efficiency, which will lower the

flexibility offered

7.2 Lessons learned

R2: What lessons can the MFF concept learn for future implementation?

The lessons presented are intended to contribute to a general standardized MFF process

concerning start-up and operation. The lessons for are presented below:

Decision-making

For the decision making to go with MFF, it can be concluded that its strength and

advantages is being flexible in; project scale and duration, location and production

technique.

MFF barriers and constraints (due to low investment costs and efficient start-up), that

must be taken into account, can be summarized as; handling complexity in offered

variations and production technique, not having efficient enough equipment, ability

to have discipline over design and early involvement as well as the existing

competition.

Early decision and involvement

Because of a longer lead-time that off-site production implies, it is required that the

decision to apply the MFF concept to a project is made early. It allows for early

involvement of project participants and expertise (e.g. design, lean, supply chain),

which is the basis for creating an efficient production.

The clients’ role is crucial to overcome procurement constrains and get the early

involvement and early decisions that are fundamental for success. The company

performing MFF achieve control over this easier by being main contractor.

Increased control - Design

To create a better design process as a prerequisite for a stable production process, the

design decisions should be taken in the last responsible moment instead of striving for

’design freezes’. It provides better conditions for creating a well thought through

initial design and provides flexibility in design to the client. After that moment, there

7 Conclusions

103

must be a loyalty to the design meaning that late decisions and changes must not be

accepted.

It needs to be a discipline in project management regarding design decisions and

changes to achieve the better design process described above.

Finding a decoupling point can be helpful to determine a strategy for offered design

variations in a MFF project. The decoupling point should be based on the capability of

the supply chain and production process and when offering variations aim for

maintaining a low variation in the production line.

Coordination of design decisions is important and dependence on another actor in

being responsible for the coordination should be avoided.

Factory friendliness

To ensure efficiency, the product needs to have a factory friendly design, which is

dependent on the complexity in production technique. The focus should be on

benefits from factory environment and not primarily using traditional construction

techniques. If using traditional construction methods, they should be kept simple,

otherwise it is difficult to achieve efficiency.

Improve and reduce complexity of the production line can be done by either

outsource parts or change parts into new methods more suitable for factory

production.

Application of DFMA philosophy on the design process reduces the complexity of

production, which contributes to factory friendly designs and a greater opportunity

for standardized production processes.

Increased control over production process

The concept should strive for short and responsive supply chains. It is an important

aspect for shifting the last responsible moment forward in time. It is also important for

being flexible regarding unforeseen events in the production process, which is likely

to occur when acting in traditional construction processes.

Control over the quality contributes to a smoother production process by reducing

risks for disruptions. Quality checks should therefore be done on a continuous basis

both during design process and production.

Lean production is an important method for achieving an efficient production

process. Creating a stable and standardized process is the most difficult part of the

method within the MFF projects. It is fundamental and striving for it should be

prioritized to lay the foundation for implementation of other lean principles.

Information technology such as ICT and RFID (e.g. BIM, Tack and Track systems)

should be integrated in the process.

Experience feedback

Because of the concept's repeated application on projects, it is important to have a

technical and operational start-up group. Measures should be taken to clearly

7 Conclusions

104

distinguish it and its functions so that experience feedback between the projects is

assured.

Labour and involvement

Greater possibilities for employing unskilled or lower skilled labour can be given

from a successful standardized production process. However, a lower skill level can

hamper innovation and productivity, which is important for the MFF concept. This

balance should not be disregarded.

It should be prioritized to choose individuals with good ability to work in teams as

well as involve them in the planning of tasks for an efficient start-up.

Most lessons can be attributed to the start-up phase, which is something stationary factories

do not have to deal with (more than once). MFF must learn to manage these to be

competitive. Be able to understand the start-up difficulties and assess the extent of start-up

are also crucial to have control over the projects’ risks. Finally and as an overall learning for

the strategic work, the results indicate that to overcome challenges for the developing the

MFF concept, the focus should primarily be on; changing the mentality to early decisions

and discipline over design, designing products suitable for factory production and finding a

basis for decision-making. The concept will then achieve stable production processes and be

applied to projects with good prerequisites for achieving its objectives. This allows the

potential of the concept to be shown and evaluate its competitiveness.

8 Discussion

105

8 DISCUSSION

8.1 Reflections and recommendations from the study's results

MFFs intended competiveness lies in flexibility in location, time and production technique,

made possible by low investment costs. However, in which extent this flexibility can be

offered, and still achieve economic viability is still not clear due to the concepts novelty.

Flexibility and keeping investment costs low comes with a price of reduced ability for

efficiency (time, cost, quality) and it is clear that MFF will not be able to compete in doing the

same things as established stationary factories. To find suitable projects (that stationary

factories do not want to or can not produce off-site), and to succeed, we believe that it will

require re-thinking, innovation and niche to have a chance to be competitive. Future pilot

projects will be essential to continue discovering which project characteristics that are

suitable and finding a viable strategic positioning. The identified strategic directions for the

MFF concept in keeping investment cost low or introducing automation indicates intentions

to balance the flexibility against efficiency. Our belief is that it is important to examine

consequences and critically evaluate the flexibility MFF should offer (by having low

investments). This is important because otherwise, there is a risk of sub-optimization where

the flexibility will be at the expense of decreased competitiveness as the possibility to

produce efficiently off-site is reduced.

Of the identified lessons in this study, some are 'heavier' than others. The categories that

have been identified as crucial for overcoming the challenges (i.e. changing the mentality to

early decisions and discipline over design, designing products suitable for factory

production and finding a basis for decision-making), can all be traced back to a

misjudgement of the extent of the difficulties that come with a start-up. It has been shown

that problems in the start-up phase can create big problems for MFF projects, problems that

might not had been as big if constructing traditionally on site. Having economic

sustainability is fundamental for the concept’s continued use and competiveness. From what

we have seen in the Battersea project, we believe that the additional costs that arise from

start-up problems in a MFF projects is crucial for MFFs viability. They constitute an

unforeseen expense and may ultimately undermine the purpose of a low investment cost. In

line with the findings, we therefore believe that the start-up phase is the most critical for a

MFF project. We believe it is essential that the development is focused on creating efficient

solutions, for the problems to be prevented. The current solution seems to be a standardized

process for start-up, operation and closedown. What this means is however still unclear and

questions that we are having are; is it possible to standardize when the needs are different

for each project (assuming full flexibility in location, time and technique)? What can in that

case be standardized when being flexible? Difficulties in standardizing projects rather than a

8 Discussion

106

continuous process, is about succeeding in achieving a sufficient start-up and to be effective

without investment costs has proved to be complicated and difficult.

It seems reasonable, however, to standardize a process, for example to find the right kind of

factory building, finding the right way to hire temporary staff or finding suitable forms of

contracts and how the physical set up of a factory occurs. However, because the risks and

difficulties primarily is linked to other factors which affects the extent and complexity of the

start-up, there needs to be a way to standardize key activities that affect this such as making

sure there will be early involvement of expertise and discipline over design decisions. Our

assessment is that the understanding of the importance is not to the extent desired. However,

understanding comes with experience and being temporary hampers that. The link to how

knowledge should be transferred between projects is still missing. We believe that the

experience feedback will be a big challenge for the MFF concept as being temporary means

turnover of the project organisation. A way to get the experience feedback to really work

needs to be found. This is important for off-site production in general, but even more

important for the MFF concept since it has no possibility to build in the knowledge in a

continuous production process.

However, the MFF concept is in its pilot phase and is thus not a fully developed concept. It is

understandable that problems arise as this involves breaking new ground. Development

takes time and there must be an understanding for that. We believe that the concept has the

potential to be a way to increase the efficiency in the construction industry by being a

complement to traditional construction. This however, is based on that there will be

continued strategic work together with critical examination of what the level of offered

flexibility should be. To be competitive, the level of flexibility needs to be balanced against

how efficient the concept must be.

8.2 Reflections on the study and its practical significance

As the MFF concept is not a fully developed concept, this study has aimed to describe the

concept and its potential as propositions based on its current state. These should be seen as

suggestions for a definition rather than generalizable knowledge. As such, it does not give a

definitive picture of what the concept is or might be. The description has been given at an

overview level, which also was the purpose. This is to give an overall understanding of the

MFF concept and thereby provide a wide springboard for further strategic and theoretical

development. The description was set to concern characteristics and positioning in the

construction industry. However, in its current state with pilots, the concept has not shown

any clear positioning as it is still discovering what the positioning should be. Therefore,

attempts have instead been made to describe the concept by its similarities and differences

with off-site production strategies in general. Strategic positioning is nevertheless important

for the future development and the identified describing characteristics can be the basis for

8 Discussion

107

continued evaluation of what MFFs optimum positioning in the construction industry

should be.

The identified opportunities for development and strategic advice are presented as lessons.

However, as these are based only on the two pilot projects, more opportunities may be

identified in the future when the concept is fully trialled. The lessons from Lean and DFMA

were few and not deep. This was mainly due to that the extensive problems in the start-up

and subsequent production interruptions prevented the application of theory to reality and

focus on start-up problems got instead a bigger place. Anyway, this study shows that DFMA

and lean philosophies are central to the MFF concept and will be applicable to a greater

extent in projects where a steady state is reached faster. Lessons from similar concepts have

also been investigated at a shallow level. These studies have however been important to

demonstrate the strategic directions that the concept can take.

In summary, this study contributes to increased understanding of the MFF concept. We have

succeeded in creating a framework based on seven propositions explaining the MFF concept

by 'pulling together loose ends' as information, knowledge and experiences have been

gathered and processed. This is something that has not been done before within an academic

context. The theoretical framework can facilitate the assessment of future strategic

development and serve as a theoretical basis for further research of the concept's definition,

applicability and potential. Last but not least, the lessons for strategic development created

in this study can help in increasing the concept's efficiency. As such, it is our hope that this

study will contribute to finding MFFs possible potential so that it can be a way to increase

the efficiency in the construction industry.

8.3 Reflections on the study’s methodology

We have entered the development of the concept with "new eyes" in accordance with the

inductive approach. Since we did not have much knowledge about the concept, it prevented

us from having substantial preconceptions, which according to Yin (2007) limits the study’s

distortion. The fact that we at the start had a lack of knowledge about the concept has also

meant that the way in which data has been gathered may not have been the most effective as

the ‘right’ questions could not be asked, etc.

Worth mentioning is also that we have chosen to study documents that had the purpose of

"selling in" the concept (founding application and an institutional journal article). This means

that there might be an excessive positive view given of the concept. The same applies to the

people chosen for interviews; they all have been involved in the research project and

therefore have the concept's success as a common interest. Also, as we participated in the

observations, we got involved in the group, which increases the risk of not being objective.

8 Discussion

108

Although this is something that inevitably reflects in the results, this is also something that

we were aware of and attempted to consider when collecting data.

The data collection has been limited in time and access. However, considering the state of the

development of the concept were only two pilot projects exists, this study had access to the

core information. What we believe could have improved the study is if we would had more

information about economics and contract conditions for the pilot projects. That could have

provided a better picture of how well the projects has succeeded to fulfil the objectives and

obligations (so far for the Battersea project). The respondents where chosen to give a holistic

view over the concept. However, we consider that the results of the study could have been

even more valid if there had existed possibilities (in time) for more interviews, from several

actors and with other involvement in the MFF.

The different ways of triangulation as a case study enables, has been a key to create theory in

an area, which not previously has been studied. The study has been executed and reported

with accuracy to ensure validity and reliability in the way presented in 2. Methodology and

data collection. Our hope is that it results in that the study is considered valid and reliable.

8.4 Suggestions for further research

As a summary of the reflections, some suggestions for further research for exploring the MFF

concept are presented below:

How should the MFF concept balance between flexibility in keeping the investment

costs low and achieving an efficient production?

What can and should be standardized in the MFF process while maintaining its

flexibility in location, time and production technique?

How can it be assured that lessons learned is transferred between the temporary

projects?

How can MFF projects best apply and make use of manufacturing methods such as

DFMA and lean philosophies (both for start-up and steady-state)?

109

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Appendix A

APPENDIX A – THE BATTERSEA PILOT PROJECT: FACTORY AND

PRODUCTION PROCESS

Actors in this project are;

Actor Involvment

Skanska UK Contracted for MEP work

Carillion Main contractor, Skanska’s client

Clark and Fenn Subcontractor in this project, hired to perform boarding

Exelin Partner to Skanska through the research project. A manufacturing advisory business, working with lean improvements in this project

University of Reading Partner to Skanska through the research project. Their work aimed to implement use of portable 3D technology in this project

BRE Partner to Skanska through the research project. A consultancy organisation which in this project works with implementation of the RFI-based ‘Tag-and-Track system’

Facilities and adjacent Skanska factory

Skanska hires an industrial unit in a trading estate in Slough, in which they have set up the

temporary factory for the utility cupboards. The factory includes a main factory space and

associated personnel facilities such as offices, kitchen and toilets. The factory space measures

about 15x30 m. It has concrete floors and an industrial port for transportations.

Skanska has an existing business in an adjacent unit. It is a stationary factory prefabricating

MEP components to Skanska projects all over the UK. They are prefabricating, among others

things, the pipe work that Skanska is responsible for in the Battersea development. Some of

that pipe work will be installed in the Circus West project where they will be connected to

the apartments by being drawn over the ceiling and under the slab in the corridor. Another

example is pipe works of bigger scale, which are eight meter long pipe parts for gas to be

connected on site.

Factory layout

In the factory, the production is organised into seven rows of cupboards. The rows are

separated by colour markings, where a yellow area marks the walkways and workspaces

around the cupboards. The plan is that every cupboard has it one space during the process

Appendix A

and that the work stations (i.e. operatives) move to them. However, for a various of reasons,

they have around 30 units in production instead of the 20 it was planned for.

In one corner of the factory is inventory storage of the larger installation components such as

the boilers and ventilation units. At the opposite corner is a larger workbench and two

shelving for storing all sorts of tools, fasteners etc. At this space is also material storage for

building material such as plywood and installation rails.

Production process

Below is a description of the work and the workflow of the production presented. It is based

on the observations and descriptions that the authors obtained during site visits as well as an

on-going documentation from a PhD student1. Figure 1 illustrates a drawing of the final

appearance.

1 Modern Flying Factory: Utility cupboards at Slough Factory – Production/Manufacturing processes by

Young, B. E. [Document in working progress 2014]

Appendix A

Figure 1 A drawing of the final appearance of the cupboard.

1. Steel frame

Number materials/component types included: 1

The structure of the cupboards is a steel frame with primer-painted steel and a

rectangular hollow profile. The steel frame is enhanced with an approximately two

decimetre wide steel plate on the back panel to take the load from the units to be

installed on its back wall later. The frames are welded together and painted by

suppliers and when delivered they are stored in the adjacent existing factory and

taken to the MFF factory as the production of new cupboards starts. A loader is used

to lift and transport them between delivery, storage and the factory. The part of the

steel frame, positioned at the threshold for the doors to the cupboards is attached

with bolts that easily can be removed on site. This part will then be waste and is only

there to hold the cupboard together when transported.

Appendix A

2. Boarding – plywood

Number materials/component types included: 1 + fastening advices

The steel frames are boarded with plywood, which are delivered pre-cut in the right

size. The back panel is boarded from the outside while the other sides are boarded

from the inside. The plywood is attached with a screwdriver. The top panel is

delivered with most of the holes pre-drilled. The joints between the plywood parts at

the back of the cupboard are strengthened with 4 nailing plates per cupboard. The

boarding is not being done by Skanska’s own labour, it is being done by labour hired

from a construction firm called Clark and Fenn.

3. Identification and quality tags/sheets

Since there are lots of variations of the cupboards, they all have a unique identity

displaying the predetermined apartment it will be fitted in. All cupboards are tagged

with A4- plastic wallets, which are taped onto the plywood on the side panel of the

cupboards, see Figure 2. Identification is given by apartment reference, size, left or

right handed, type of MVHR (Mechanical Ventilation with Heat Recovery) and

CCHU (Boiler unit) and delivery date. This identification follows the cupboard until

the final installation on site. A plastic wallet for quality check sheets is taped on the

opposite side panel of the cupboard.

Figure 2 Example of an identification sheet for one of the cupboards.

4. Insulating the top panel


Appendix A

For acoustic reasons, the top panel is insulated with mineral wool.

5. Boarding – plasterboard

Number materials/component types included: 1 + fastening devices

The inside of the back and side panels as well as the front stripes (frame where the

door is going) are boarded with one layer of 15 mm plasterboard. The top has a

double layer of 15 mm plasterboard, for acoustic reason. The plasterboard is pre-cut

in the right size from the supplier except for the front stripes. The plasterboards are

not pre-drilled for the penetrations, since they would then be too fragile to transport.

All plasterboard is attached with automatic screwdriver. A template is used to drill

the holes for penetrations, which are being done with a hole cutter. As well as the

plywood, the plasterboard boarding is being done by labour hired from Clark and

Fenn.

6. Taping, jointing and painting


All corners, joints and unevenness are taped and jointed. The taping is being done

with a hand machine. This procedure takes a long time because of the time to dry

between. The procedure is; Taping/jointing 1 – drying time – sander/jointing 2 –

drying time – sander/painting 1 – drying time – painting 2 – drying time. This work is

being done by a painting company who comes to the factory when it is required. It is

common that rework has to be done by the painters, since the surface is easily

damaged.

7. Installation of Heat Interface Unit (HIU)


Pipes are connected to the top of the HIU, before the HIU is fitted onto a steel bracket

that is attached to the back panel. During the fitting, the HIU is carefully lifted into

place with a lifting device to fit the pipes in the top holes.

8. Installation of electrical sub and trunking

Number materials/component types included: approximately 5-8 + fastening devices

In this stage, all electrical components are installed into the cupboard (see Figure 3)

such as the residual current device (RCD), consumer unit, the broadband & TV (BT)

box and the AV box. All electrical conduits are installed and the HIU are connected.

The main electrical conduits go through and along one of the side panels. A peace of

wood helps to keep the electrical conduits in place until they are being connected and

fixed on site.

Appendix A

Figure 3

Photo from the factory, electrician working on electrical sub and trunking.

9. Installation of Mechanical Ventilation with Heat Recovery (MVHR)


MVHR is a heat exchanger between the inbound and outbound airflow. Associated

ventilation spigots are unscrewed to be able to seal the connection with foam. The

ventilation spigots are then re-installed together with the pipes. The ventilation unit

is lifted with a lifting device, same as the one used for the HIU. The lifting has to be

done carefully to fit the pre-drilled holes in the top of the cupboard.

10. Installation of water pipes, water meter, drainage and access hatch

Number materials/component types included: approximately 4-6

All water pipes including the water meter and drainages from the HIU and MVHR

are mounted into place. The main pipes goes through the module sidewall in waiting

for later connection to the rest of the building on the construction site. In this stage,

an access hatch is also installed on the sidewall for possibility of inspection. The

welding of the copper pipes is being done outdoors (just outside the port) and

manually by Skanska’s own labour.

11. Installation of Passive Infrared Sensor (PIR) and lighting


In the last stage the lightning unit and related motion detector (PIR) are installed.

Appendix A

12. Complementing electrical work

Number materials/component types included: approximately 2-5

All components are connected and lids are fitted.

13. Insulation of water pipes

Number materials/component types included: 1 + tape

Pipe insulation of the type Armaflex, are fitted by a hired insulation specialist to get

the right finish, see Figure 4

Figure 4 Pipe insulation of the type Armaflex.

14. Pressure and electrical test

Water pressure and electrical testing are performed and documented.

15. Wrapping

The modules are wrapped with plastic and tape and corners protected from straps

during transport with cardboard corners, see Figure 5.

Appendix A

Figure 5 Photo from the factory, cupboard wrapped and ready to be delivered.

Workflow

The production process described above is an approximate description of the flow. What

could be seen during the observations in the factory was that the procedure of work varied

between the cupboards. Mostly it was an outcome of waiting for decisions, components, a

need to prioritize and due to rework. Since the cupboards are not that smoothly moved, the

work is being done where the cupboard stands. That means that the labour and material are

being moved to the units.

Equipment

All work is being done manually. Equipment used is for example crosscutters, screwdrivers,

electrical drills and welding equipment. For lifting, they are using manually operated

hydraulic lifters when moving the cupboards (see Figure 6) and another lift for the boiler and

ventilation unit (HIU, MVHR). For access to work on the top of the cupboards they are using

a scissor lift and a small scaffolding. Commonly used tools are kept in a tool wagon that can

be moved between the cupboards.

Appendix A

Figure 6 Photo from the factory, hydraulic lifters used to moving the

cupboards.

Measures

For some of the measures for positioning that are the same, templates are being used, where

a steel sheet for the MVHR and HIU brackets is an example. Something that is discussed is to

increase the use of templates to improve the process.

Storage

Most of the material and components are stored in the factory such as plasterboard,

plywood, boilers (HIU), ventilation units (MVHR), electrical and plumbing components as

well as tools. As been mentioned before, most of the small components and material are

stored on shelves in one corner of the factory. Some office rooms are used for storage to

accommodate all material. The steel frames are stored in an available space in Skanska’s

adjacent factory along with finished cupboards, which will go out for delivery.

Transports/moving the cupboards

Transports within the factory (to the port and sometimes other unplanned moving) are being

done with two of the hydraulic lifters, which are clamped together with straps. To get access

with the hydraulic lifters, all cupboards are distanced from the floor by standing on steel

profiles. Two persons are needed to move the cupboards. For lifting them on site, the steel

frame has lifting points on the top where strops or chains can be attached. Transportation

between the buildings for storage is being done with a loader.

Appendix A

Quality checks

In the plastic wallet that goes with every cupboard, there are three different sheets with

quality checks for the cupboards; a pressure test certificate, electrical circuits test and details

and inspection checklist for electrical as well as mechanical services. It includes for example;

checking cupboard size and measures, confirm components are fitted correctly and checking

levels. It is also possible to make comments if there are deviations or errors. The quality

checks are to be completed by the person directly responsible for the work. In the current

state, this is done randomly. However, the sheets are completely signed before the

cupboards leave the factory.

Variations

All cupboards have a unique apartment number and the design can vary within;

Right and left handed

Two different widths

Different kind of boilers, HIU

Two different depths

Workforce - Skanska and hired labour

As been previously mentioned, all work in the factory is being done by Skanska’s own

labour, accept for the boarding (plywood and plasterboard), taping jointing and painting as

well as the insulation of the water pipes. Skanska has an agency through which all the

Skanska labour is recruited.

Skanska has two electricians and two plumbers working with the cupboards. This number

can be changed quickly if the site manager needs a bigger workforce for a period because of

a flexible lease from an agency. The electricians are mainly doing the electrical work and

plumbers are mainly doing the plumbing work. However, they are also doing other things

that are not typically work they are trained to do, like moving cupboards around, making

templates for drilling holes or cutting holes for the access hatch.

The hired labour for boarding from Clark and Fenn is usually one man coming for a few

days to do a certain amount of cupboards.

The hired labour for taping, jointing and painting usually consists of teams of two and three

and comes for a couple of days to do work on cupboards that are boarded.

Test-facility

A test of the cupboard and parts of an apartment were built mainly to test the acoustic

qualities but also the assembly of the cupboard. It was built from the initiative of Skanska in

Appendix A

the first place (in order to benchmark the product) and by Carillion, the main contractor who

need to ensure those they have to build will be built to suitable standards. This was a success

according to the Site Manager and has been useful for testing the structural frame and the

ventilation unit. It has led to changes, which would not have been possible to test until the

whole building was constructed on site. The testing discovered that the ventilation unit did

not meet the acoustic requirements and changes had to be made. That is an example of

something that could have been a higher cost to discover in a later stage.

New materials

The new constructions discussed are both new and existing materials that would be used in

a new way according to the Site Manager. Two of the products they are looking at are P2P

(Panel 2 Panel) and TEK Panels (Kingspan). Since the use of both materials in this particular

way would be new they will have to be appropriately tested before they can be used.

P2P – made from recycled plastics and self supported. Would be possible to attach

the component direct on the material and could be supplies pre finished. It could also

be pre cut and drilled in the factory before delivery.

TEK panels – a Structural Insulated Panel (SIP) with an insulated core sandwiched

between two layers of OSB. Could be pre cut in the right size.

Tag and track

Initial meetings with Building Research Establishment (BRE) are taking place for discussing

possible application of a ‘Tag and Track’ system. BRE will develop a product with a system

that suits the production of cupboards. The cupboards would be tagged with barcodes and

scanned with handheld devices. The handheld devices would display and receive

information and all information would be stored on a server. The system would have

different kind of users and accesses for labour and management. The server would be

connected to wifi. The site manager would have access to all information direct and with

filters sort out the information needed. However, the development of this software system

takes time. Observations was made of an initial meeting an it was shown that it is complex

and important to sort out the basics of the software to make it useful, during the meeting it

was noted that they would try to keep it simple in its first version, and stick to main

functions useful for this project.

It needs to be found out set-ups, functions and information that the software should contain

to be useful for the work and planning of the factory. The two main functions that where

discussed where;

Appendix A

Important dates. To facilitate the planning each cupboard should be tagged with

important dates and history of changes for these: Building date, Original delivery

date, changed delivery date, real delivery date.

Quality check lists. The checklists that today are sheets glued to the side of the

cupboard would instead be on the tag. The quality checks would be done and

registered with handheld device.

It was also noted that they saw great potential in developing the Tag and Track system.

Other functions discussed as future potential where;

Improved quality assurance by tracking the faults. If a fault is discovered, early or

late stage, it can be tracked and other units likely to be affected can be checked again.

If the start and end of each task was registered, it could give time data that could be

useful for controlling and work with improvements in the factory.

Appendix B

APPENDIX B – PROBLEMS IDENTIFIED IN THE BATTERSEA

PROJECT

The table below presents problems that were observed during site visits at the factory in

Slough as well as problems that wereyli highlighted during interviews. The column that

indicates if the problem is considered to be related to the choice of producing off-site has

later been added for the analysis and is based on the authors’ interpretation.

Appendix C

APPENDIX C – INTERVIEW QUESTION SHEET, SITE MANAGER

Interfacing

1. Can you tell us about how the design work was carried out to insure right

interfacing? (Make sure that the module would fit into the rest of the building?)

- Which steps were taken to make sure the interfaces of the design worked

with the rest of the building?

- When? By whom?

Start-up and operation of the project

2. Which were the biggest production risks identified before the start of production and

how were they handled?

- Problem after production start?

- If yes, how were the problem(s) dealt with after production start?

- Problem(s) avoided – if handled in a different way?

3. Which main difficulties have been encountered during operation of the production

process in terms of:

- Production (We know the main issues but can you summarize the most important

of them)

- Design

- Labour

- Suppliers

4. To what extent have the workers been involved in decision-making and planning

through the different stages of the project?

- How were skilled workers introduced at start-up and how are they

introduces today?

- Were the workers involved in the planning process at start-up?

5. How much consideration was given to the learning period when planning the project

and what are the outcome?

Were tasks more complicated than you first thought they would bee?

- Did the length of the actual learning period correspond to the estimated

and planned length?

- Has any steps been taken to shorten the learning period?

6. On which basis has procurement of the project's subcontractors and suppliers been

done and how has the collaboration worked?

- Is it based on best price or further collaboration?

7. Are there any lessons learned from the straw bale panel project in Bristol that have

been useful in this project?

Improvements in the production process

Appendix C

8. Can you tell us about the purpose and execution of the lean improvement work in

this project?

Which improvements have been carried out? How has it been done?

- Extent and purpose to implement?

- What does the organization behind the implementation of lean look like?

What responsibilities does each actor have?

9. How is the production controlled, regarding communication, progress and errors?

- Which tools for planning are used?

- How are work tasks communicated?

- How are work progress followed up?

- How are errors in the production process handled?

- Are there any procedures for implementation of improvements?

10. Can you tell us how the pace is kept in the production process and how bottlenecks

are dealt with?

- How is it determined when work on new modules should be commenced?

- What tools are used to control the pace (takt time) in the production

process?

- How much consideration is given to the coordination between workstations

in order to keep the pace (takt time)?

- Which are the bottlenecks?

The production process in total

11. In general, what do you think has been successful in the planning and control of the

production process?

The concept and it´s future

12. Which characteristics made this project appropriate as an Modern Flying Factory?

- Characteristics for/against off-site techniques?

- Characteristics for/against temporary factory?

- Stationary factory suitable instead of a temporary factory?

- Which is the minimum quantity for a realistic chance to be economic?

13. Is there anything else you think have been done well in the project that you want to

highlight?

14. Can you tell us what you think of the future potential of the concept Modern Flying

Factories?

- Is there a future?

- Have you thought about other suitable building components?

Appendix D

APPENDIX D – INTERVIEW QUESTION SHEET, SUSTAINABILITY

MANAGER

Decisions

1. Tell us what the background and purpose with the project are?

2. How did the idea of the project (not the concept) start and developed?

- Where, who, how?

3. Which decision basis was used to carry out the project as a MFF?

- Example cost estimates, risk analysis

4. What is the main purpose of carrying out the project as a MFF?

5. Which professionals where involved in the decision to carry out the project?

Characteristics and experience feedback

6. What are the characteristics that make this project appropriate for use of a temporary

factory?

- Are there characteristics that not make this project ideal for use of a

temporary factory?

- For this project, could a stationary factory have been suitable instead of a

temporary factory?

- Which quantity of units would be a minimum for the project to have a

realistic chance to be economic?

7. How do you make sure the experience from this project will be carried through to the

next project?

- Is there some lessons learned from the straw bale panel project in Bristol

that has been useful in the cupboard project in Slough?

- Has it been any experience feedback between the two projects?

- Has the processes for the two projects been documented?

Future - the concept in total

8. What are the future plans and potential of MFF?

- Are there plans for further development of the concept MFF?

- For which parts of building are there potential for use of MFF?

9. Is there anything else regarding the MFF that you want to highlight?

Extra questions

10. Which expectations where there on the project (economy, time, quality, labour)?

- What are the expectations on the project in terms of economy, time, and

quality?

- What are the expectations on the project in terms of labour and skill level?

Appendix E

APPENDIX E – INTERVIEW QUESTION SHEET, LEAN CONSULTANT

Outcome (only the Glenfrome project)

1. What are your thoughts about the outcome of the project in terms of economy, time,

quality, labour and/or others?

2. Which where the main difficulties that occurred during the project?

- How did the work of overcoming these difficulties proceed?

3. Did something go above expectations?

- If yes, what went over expectations and why?

4. What would you say, is the most important thing to do differently next time?

- Are there any lessons learned from this project that have been useful in the

project in Slough?

- Has the process been documented?

5. Is there anything else regarding the project that you want to highlight?

Improvements in the production process

6. Can you tell us about what the purpose and execution of the lean improvement work

was in the project?

Which improvements were carried out? How was it done?

- Extent and purpose to implement?

- What did the organization behind the implementation of lean look like?

What responsibilities did each actor have?

7. Can you shortly tell us how the production was controlled, regarding

communication, progress and errors?

- Which tools for planning were used?

- How were work tasks communicated?

- How were work progress followed up?

- How were errors in the production process handled?

- Were there any procedures for implementation of improvements?

8. How much consideration was given to the learning period when planning the project

and what were the outcome?

Were tasks more complicated than you first thought they would bee? Examples design

changes, learning/induction for workers, production methods.

- Did the first delivery go out in time?

- Was it more complex than you thought?

The concept and its future

9. Do you have any thoughts about what made the project suitable for a temporary

factory?


Appendix E


10. Is there anything else you think was done well in the project that you want to

highlight?


Factories?



Appendix F

APPENDIX F – INTERVIEW QUESTION SHEET, DESIGN DIRECTOR

Outcome

12. What are your thoughts about the outcome of the project in terms of economy, time,

quality, labour and/or others?

13. Which where the main difficulties that occurred during the project?

- How did the work of overcoming these difficulties proceed?

14. Did something go above expectations?

- If yes, what went over expectations and why?

15. What would you say, is the most important thing to do differently next time?

- Are there any lessons learned from this project that have been useful in the

project in Slough?

- Has the process been documented?

16. Is there anything else regarding the project that you want to highlight?

Execution

17. How were the contract and relationships carried out?

- What type of contract form did the tender documents specify and which

kind of contract was the project procured on?

- Was the design already done, was the design already suitable for off-site

techniques?

18. How was the work with design concerning interfacing carried out?

- How many times have you worked with off-site production projects?

- Which steps were taken to make sure the interfaces of the design worked

with the rest of the building?

The concept and it´s future

19. Do you have any thoughts about what made the project suitable for a temporary

factory?



20. Is there anything else you think was done well in the project that you want to

highlight?


Factories?



Appendix G

APPENDIX G – INTERVIEW QUESTION SHEET, MANAGING

DIRECTOR

Background and purpose

1. Why is Skanska interested in using and developing off-site techniques in the

construction?

- Which are the main purposes for using off-site and not only traditional

build?

- How do you look at the benefits time, cost and quality by using off-site

techniques? Which of them is of most importance?

2. Tell us what the background and purpose with the concept are?

- From which grounds and needs did the idea of the concept start and

developed?

- Of all these benefits, can you please point out the most important for using

the concept? What is the core of MFF?

3. Why invest in MFF as an off-site strategy?

- Which are the driving forces within Skanska that makes investing in MFF

suitable instead of other off-site strategies? (Which are the benefits

compared to others?)

- Why not invest in stationary factories or buying prefabricated building

systems (by others)?

Risks and generally

4. Is there a risk that MFF project are too complex to use un-skilled labour?

- …Since projects have a limited duration and start-ups can be tricky and

often needs skilled labour?

5. How do you see the problem with the low skill levels in the industry?

- Is MFF a long-term solution?

6. Since the labour should be of a low skill, how important is the skill level and training

of the design and production management?

- How is the knowledge kept in the company? And how is the knowledge

carried through to the next project?

- Do you have any strategies (other than the toolkit) to make sure that the

skill level is high?

7. What is your view on early involvement from MFF professionals in the design work?

(lean, production management)

- How important is it?

8. How important is the contract type? Which contract is optimal for the use of MFF?

9. How does decision-making process look like when choosing an appropriate MFF

project?

Appendix G

- For example in Slough?

- On which basis? Economical criteria?

10. Can you tell us about how the finance for the development of the concept is handled?

Are the projects carrying the costs or does a development founding support them?

- How has it worked in the Slough project?

- Which strategies or measures will be used to achieve early involvement?

- Where does the founding for the development come from? (Skanska or

TSB?)

Outcome and future

11. Do you or Skanska have experience of temporary factories of any kind (field

factories)?

12. Which potential markets or market segments do the MFF concept has?

- What are the limitations?

- For which level of complexity is the concept suitable? (Slough and

Glenfrome are very different)

- What do you think about the level of technology in the production? Should

automated processes be implemented?

13. What do you think about the outcome of the pilot projects so far?

- Did they fulfil the expectations? Economical? Glenfrome?

14. What are the future plans and potential of MFF?

- Are there plans for further development of the concept MFF?

- For which parts of building are there potential for use of MFF?

- What does the future look like for Battersea?

15. In a scenario that Slough is not profitable, what will then happen with the concept in

the future? Will it be continued?

16. What do you see as the biggest barriers for success?

17. Is there anything else regarding the MFF that you want to highlight?