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Abstract

Schedule delays commonly occur in construction projects and often result in delay claims. However,

there is no well recognized and acceptable claim resolution approach for solving construction

schedule delays. Most available methodologies are processes-based approaches but not computerized,

which should be executed by schedule analysts manually. To solve schedule delay problems related

with lost productivity, a previous study proposed a delay analysis method that integrated a lost

productivity calculation approach into the collapsed as-built method. The purpose of this study is to

implement the developed methodology on a project management system. This study first detailed the

processes of delay analysis, which provided a fundamental to select a suitable development tool for

implementing delay analysis processes. Second, this study evaluated the potential tools in

implementing delay analysis methodology. One of popular project management systems was selected

because it provided flexible program development functionality and it had high performance in

schedule management. Based on the results of process analysis and development tool selection, this

study then developed a system prototype for solving the schedule delay problems with lostproductivity. The developed system not only calculated accurate delay amounts for each activity and

clear delay liability for contract parties, but also reduced analytical time due to computerizing tedious

computational processes. Finally, the practicability of developed system had been examined by a

simplified real case. In sum, this study developed a prototype system to help schedule analysts to

solve their schedule delay problems on project management system.

Keywords: Schedule Delay Analysis, Construction Project, Project Management System.

1 IntroductionSchedule delays commonly occur in construction projects and often result in delay claims. However,there is no well recognized and acceptable claim resolution approach for solving construction

schedule delays. Several studies have proposed different schedule delay analysis methodologies for

performing delay analysis systematically. The common used methodologies include global impact, net

impact, adjusted as-built CPM, as-planned expanded, but-for, snapshot, time impact, windows,

isolated delay type techniques and isolated collapsed but-for delay analysis methodologies (Ng,

Skitmore et al., 2004; Mohan and Al-Gahtani, 2006; Yang and Yin, 2009). In general, by using the as-

planned or as-built schedules as baseline schedules, available methodologies calculate schedule

impacts of delayed events according to the differences between the baseline schedules and some

entitled impacted schedules that are derived from delayed events. Furthermore, most available

Implementing schedule delay analysis methodology on projectmanagement system

Jyh-Bin Yang

Graduate Institute of Construction Engineering & Management, National Central UniversityKuei-Mei HuangPh.D. Program of Technology Management, Chung Hua University

Ciou-Mei Chen and Shao-Chu LiuDepartment of Construction Management, Chung Hua University

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methodologies are processes-based approaches, which are executed by schedule analysts manually. In

other words, if project schedules are complex, the processes for completing required delay analyses

are tedious and time-consuming. Most of the methodologies mentioned above are not computerized.

That is, the schedule delay analysts should complete their works manually although their available

schedules are generated by professional scheduling systems or project management systems.

Lost productivity means completing planned work at less planned rate of production (Trauner,2009). In construction projects, contractors often suffer certain damages from lost productivity when

delaying as-planned schedules. To solve schedule delay problems associated with lost productivity, a

previous study has proposed a delay analysis method that integrated a lost productivity calculation

approach into the collapsed as-built method (Yang et al., 2011). Similar to available common

schedule delay analysis methodologies, the approach proposed by Yang et al. (2011) required

schedule analysts with professional skills to spend pretty time in analysis. Namely, using that

approach to solve schedule delay problem with lost productivity is still tedious and time-consuming.

Based on above introduction to research background and motivation, the purpose of this study is to

implement a delay analysis method with considering lost productivity on a project management

system. This paper is organized as follows. Section 2 discusses the processes for delay analysis, which

provides a fundamental to select a suitable development tool for implementing delay analysis

processes. Section 3 evaluates the potential tools for implementing delay analysis methodology.Section 4 introduces the developed system prototype for solving the schedule delay problems with

lost productivity, and the implementation of developed system on a simplified real case. Section 5

concludes some findings and potential future research directions.

2 Processes of delay analysis2.1 General delay analysis processesFor solving encountered schedule delay problems, Schumacher (1995) proposed four questions to

help delay analysts clarifying their delay problems: What was supposed to happen?, What did

happen?, What were the differences? and How did they affect the project schedule?. Based onthe viewpoint of Schumacher, Kao and Yang (2009) organized delay analysis as a four-phase task.

The phases consist of determining baseline schedules, building updated schedules, executing delay

analysis and allocating responsibilities of delays.

Before executing delay analyses mentioned above, delay analysts should select a suitable delay

analysis methodology based on their available delay-related information and documents. Each

methodology has different information and document requirements. However, the as-planned and as-

built schedules are necessary for most methodologies. Furthermore, previous studies (Arditi and

Pattanalitchamroon, 2006; Kao and Yang, 2009) proposed certain guidelines (for example,

availability of information, time of analysis and capabilities of the methodology) for helping delay

analysts screening suitable methodologies. If one methodology was selected, detailed delay analysis

processes regarded to the methodology should be followed in executing necessary analyses.

2.2 Delay analysis with lost productivityIt is well known that many diversified delay factors might cause individual activities be completed

behind original schedules and consequently delayed project completion. Previous studies have

identified many common factors of delaying schedules in all stages of construction projects. For

example, the causes of late drawings and specifications delivery, slow inspection by clients

representative and unforeseen site conditions in a projects construction stage were identified

previously (Yang and Ou, 2008). Notably, above delay factors might make activities suspended or

influence them partially. The former situation is easy to quantify its impact; the latter situation is hard

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and complicated to quantify its impact, which is usually considered as the problem of lost

productivity.

In managing a construction project, a contractor usually suffers certain damages by lost

productivity caused by the owner or the third party. Lost productivity, resulting from some actions

with owners or third partys responsibility, may not be easily detected. How to calculate the schedule

impacts by lost productivity plays a key role for solving a delay claim with lost productivity.Although various lost productivity calculation methodologies have been developed (Lee et al.,

2005; Lee et al. 2011), a contractor suffering the problem of lost productivity might have no

appropriate method to quantify its damages. Furthermore, most available delay analysis

methodologies concentrated on calculating the impact of identified delay events on project duration.

They did not include delay evidence in their delay analyses. Namely, before performing delay

analysis by available delay analysis methodologies, schedule analysts should identify delayed events

and even quantify delay impacts in duration.

2.3 Simulated delay analysis proceduresA study tried to eliminate some pitfalls existed in previous delay analysis methodologies with

considering lost productivity, and proposed an innovative delay analysis method (Yang et al., 2011).The proposed analysis procedures were summarized as follows.

Step 1: to collect the as-planned schedule, as-build schedule and construction daily reports. Step 2: to clarify whether the delayed activity has the impact of lost productivity. Step 3: to collect productivity-related information, including resource usage, finished item with

quantity, and minutes.

Step 4: to identify delayed schedule caused by lost productivity. Step 5: to calculate regular and impacted productivities. Step 6: to calculate impacted as-built schedule. Step 7: to calculate the variance between the impacted as-built schedule and the as-built schedule. Step 8: to summarize all schedule variances.

Based on above steps and the methodology proposed by Yang et al. (2011), this study tried tosimulate whole schedule delay analysis approach for a construction project with lost productivity

problems.

3 Tools evaluation for system developmentSome software packages/programs for professional schedule delay analysis have been developed and

commercialized. Yang (2005) reported the results of a performance comparison between Claim

Digger (now incorporated into Oracles Primavera P6 system) and Schedule AnalyzerTM Professional.

That study concluded that existed packages/programs had some limitations including limited schedule

delay analysis methodologies involved. The discussed packages/programs in that study provided end-

users fixed functionalities for executing. Therefore, using such packages/programs to implement delayanalysis methodology discussed previously is impossible due to their capabilities of programmable by

end-users.

Recently, project management systems are popular gradually due to the wide and quick

development and promotion of project management professionals. Many project management systems

were developed for construction project scheduling. For example, Oracles Primavera P6,

BuilderTREND, and HeadsUp iCPM were evaluated as best systems for construction projects

(Software Advice, Inc., 2012). These systems were designated to help users to planning and

controlling construction projects, especially on project schedules.

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Considering the futures of system price, system programmability, user interfaces and easy-to-use,

this study evaluated several project management systems, which are popular in Taiwans construction

industry. The evaluated systems include Oracles Primavera (P3 and P6), Delteks Open Plan TM

Professional and Microsoft Project. Based on the criterion of system programmability, this study

selected the Microsoft Project version 2007 (Microsoft Corp., 2011a) for implementing selected

methodology. Microsoft Project

provides a programming language, the Microsoft Visual Basic forApplications (VBA), for users to customizing their specific requirements. In comparison with other

development tools, the Microsoft Project

and VBA offers useful assistance, including embedded

logistical rules and mathematical functions, direct Macro recording, on-line tutorial documents, and

real-time debugging description.

In sum, for improving the system usability of developed prototype, this study developed the

system prototype based on the Microsoft Project 2007 Professional version, in which programmer

can use the VBA macro tool to coding. The end-users can run developed system on the environment

of Microsoft Project

2007 and incorporate existed project schedules according to the format of

Microsoft Project 2007. This decision of tool evaluation diminishes the barriers of system

development and system usage for developer and end-user, respectively.

4 System prototype for solving lost productivity delay problems4.1 System prototypeUsing the Microsoft Project 2007 traditional Chinese version as system development platform, this

study developed a system prototype for solving lost productivity delay problems in constriction

projects. Figure 1 shows the user interface of developed system prototype. The system prototype

provides six steps designed in different tabs, respectively. A user can finish his/her analyses after

completing these steps consequently. All steps are illustrated as follows:

Figure 1. Example system dialog for developed prototype.

First, the user should upload three schedules (as-planned schedule, as-built schedule with lostproductivity impacts and a benchmarking schedule without lost productivity impacts) into the

system. When all schedules were uploaded completed, the system identified delayed activity

automatically.

Second, for each delayed activity, the user should input its start and finish dates of delay eventsrelated to lost productivity. The system customized a data sheet for data input and calculation.

Notably, although the Microsoft Project

2007 Professional version provides a working space for

user to identify resources for cost management and resource-related scheduling, it has many

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limitations in use. For productivity calculation, the information stored in Microsoft Project

for

general cost management and resource-related scheduling is not enough. This study organized a

new data sheet for productivity calculation. Figure 2 shows the customized data sheet on Microsoft

Project.

Figure 2. Customized data sheet for data input and calculation.

Third, for each delayed activity, the user should input its productivity-related information. Forexample, planned and actual resources inputs, and planned and actual complete units are required.

In general, this productivity-related information can be retrieved from construction daily reports.

Fourth, after checking the completeness of required data, the system automatically calculated thedelayed days caused by lost productivity. The system calculated the schedule impact of lost

productivity based on a proven methodology which was not discussed in this study. The result

shown in this step is the answer for schedule delay analysis with considering lost productivity.

Fifth, if the user can identify the liability (excusable delay or non-excusable delay) of scheduledelays for each delayed activity in this step, the system allocated all delay liabilities to the owner

and the contractor, respectively.

Last, the system will display final analytical results, including the total delayed duration on aproject and the delayed amounts allocated to the owner and the contractor, respectively.

4.2 System evaluationFor demonstrating its practicability of developed system prototype, this study examined the system

using a simplified real case. Table 1 shows the basic information for the demonstration project.

Notably, this project encountered the problems of land acquisition and moving existing conduits,

those made the contractor losing his planned construction productivity.

Table 1. Basic information for demonstrated project.

Feature Information

Project Name AAA Road Construction Project

Location Taichung, Taiwan

Contract Price NT$ 2,598,000,000Construction duration 1,218 calendar days

Penalty rate for delay 1/1000 of contract price per day

Identified delay events Typhoon, land acquisition, moving existing conduits

Due to the complete project schedule for the demonstration project is huge and complex, this study

extracted two independent activities for demonstration. Table 2 shows the study activities, two

drainage culvert activities. The activity N1 is a normal activity and activity D1 is a delayed activity.

Complete information for their planned and actual start and finish dates are provided in Table 2.

Figure 3 shows the complete schedule for study activity D1.

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For calculating the impact of lost productivity on a delayed activity, the user should provide some

productivity-related information, including planned resource, work quantity, actual resource used and

actual work quantity completed. Figure 4 shows the user interface for productivity information entry.

Table 2. Schedule information for study delayed and normal activities.

Type Activity Dur.

(day)

Critical Start

date

Finish

date

Dur.

(day)

Actual

start

date

Actual

finish

date

Delayed

duration

Delayed D1 72 Yes 08/03/14 08/05/24 94 08/03/14 08/06/15 22

Normal N1 80 Yes 08/06/17 08/09/04 80 08/06/17 08/09/04 0

Figure 3. Complete schedule for study activity D1.

Figure 4. Productivity information input interface.

Furthermore, this demonstration project encountered delay problems with lost productivity. Within

this demonstration case, all delayed events were caused by the force majeure which was proposed by

the contractor. Based on the viewpoint of the contractor, these delays are non-excusable delays. While

the information was identified and input, the system performed complete delay analysis. Figure 5

shows the final analytical results for the demonstration case, in which, among the twenty-two delay

days, roughly twenty-one days are entitled to the owner and one day to the contractor.

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As illustrated previously, a user can use the developed prototype system to calculate the delay

liability quickly by providing necessary information. Based on the developed system, the user

performs required schedule delay analyses by easy-to-use interfaces. Namely, through the developed

system, completing delay analysis is easy and time-saving.

Figure 5. Final analytical results for demonstration case in developed prototype system.

5 Conclusions and SuggestionsSchedule delays commonly occur in construction projects and often result in delay claims. Most

available methodologies are processes-based approaches and not computerized, which should be

executed by schedule analysts manually and make delay analyses tedious and time-consuming. Based

on a delay analysis methodology that integrates a lost productivity calculation approach into the

collapsed as-built method, this study implemented the methodology on a project management system.

Through a popular project management system, the Microsoft Project 2007 Professional version,

this study developed a prototype for delay analysis. For demonstrating the capability of developed

prototype, this study used a simplified real case to perform delay analysis. The developed system does

not only calculate accurate delay amounts for each activity as well as clear delay liability for contract

parties, but also reduces analytical time due to computerizing tedious computational processes. This

proves that the developed prototype system can help users to solve their schedule delay problems on a

project management system.

Based on the study results, two potential research issues can be performed in the future, those

include:

Providing more user-friendly interfaces for end-users. The developed prototype limited the user toinput productivity information through a customized data sheet and to provide project schedules in

the format of Microsoft Project

2007. This limitation makes the user must be famous with the

project management system in advance.

Examining the prototype using additional complicated cases. This study tested the prototype usinga simplified real case only. More examinations by using additional complicated cases provide

more convince evidence to prove the capability of developed system.

Acknowledgements

The authors would like to thank the National Science Council, Taiwan, ROC, for financially

supporting this research under Contract No. NSC-100-2221-E-008-117.

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