THESIS FOR DEGREE OF DOCTOR OF PHILOSOPHY

Environmental Improvements of the

Post-Farm Dairy Chain:

Production Management by Systems Analysis Methods

JOHANNA BERLIN

Department of Energy and Environment

CHALMERS UNIVERSITY OF TECHNOLOGY

Göteborg, Sweden, 2005

Environmental Improvements of the Post-Farm Dairy Chain:

Production Management by Systems Analysis Methods

JOHANNA BERLIN

© JOHANNA BERLIN, 2005

ISBN 91-7291-655-9

Doktorsavhandlingar vid Chalmers tekniska högskola

Ny serie nr 2337

ISSN 0346-718X

ESA Report 2005:6

ISSN 1404-8167

Department of Energy and Environment

Division of Environmental Systems Analysis

Chalmers University of Technology

SE-412 96 Göteborg

Sweden

Tel: +46 31 772 10 00

http://www.esa.chalmers.se

Telephone to author: +46 31 335 56 00

E-mail to author: johanna.berlin@sik.se

Chalmers Reproservice

Göteborg, 2005

III

Environmental Improvements of the Post-Farm Dairy Chain: Production Management by Systems Analysis Methods JOHANNA BERLIN Department of Energy and Environment Division of Environmental Systems Analysis Chalmers University of Technology Abstract The production of dairy products is becoming more centralised at the same time as the number of different products is steadily increasing. In this thesis, the environmental impact of such ongoing development trends in the post-farm dairy chain was evaluated and improvements were suggested. Methods for production management and environmental systems analysis (life cycle assessment, material flow analysis and substance flow analysis) were combined and used in the evaluations. A first assessment of potential future developments in the dairy chain showed that the least preferable scenario from an environmental point of view was the one most similar to trends in the dairy chain of today. Subsequent investigations revealed the same result. Large dairy units with long distance transports lead to a higher environmental impact than small dairy units. On the other hand, small dairy units are those for which the environmental impact is affected the most by the rising variety of cultured products. The changed consumption patterns towards more cultured products and cheese, instead of milk, cause an increased environmental impact with regard to the cultured products, whereas for cheese no clear effect was found. To enable counteraction of negative environmental effects of increased product variety, a method to sequence the production of cultured dairy products with as little environmental impact as possible was developed. The method combines production management methods and environmental systems analysis. A heuristic solution to the sequencing problem was developed and, to the extent possible, validated with an optimisation. The method was used in a case study which revealed not only the importance of a waste minimised sequence but also that of a low production frequency. Life cycle assessment was combined with an actor analysis to examine the potential of the actors in the post-farm chain (dairy, retailer and consumer) to decrease the environmental impact of dairy products. Cutting down waste of product proved to be an effective way to reduce environmental consequences. Saving energy and improving transport patterns gave in general smaller reductions. Choosing organic products decreased most environmental categories at the expense of increased eutrophication. Keywords: environmental systems analysis, life cycle assessment, LCA, environment, dairy, dairy products, cheese, yoghurt, production scheduling, actor analysis

V

List of Publications

This thesis is based on work reported in the following five appended

publications which are referred to by their Roman numerals in the text.

Paper I Sonesson, U., and Berlin, J. (2003). Environmental Impact of Future

Milk Supply Chains in Sweden: A Scenario Study.

Journal of Cleaner Production 11:253-266.

Paper II Berlin, J. (2002). Environmental Life Cycle Assessment (LCA) of

Swedish Semi-Hard Cheese.

International Dairy Journal 12: 939-953.

Paper III Berlin, J., and Sonesson, U. (2005). A Life Cycle Based Method to

Minimise Environmental Impact of Dairy Production through

Product Sequencing.

Journal of Cleaner Production, In print.

Paper IV Berlin, J., Sonesson, U., and Tillman, A.-M. (2005). Minimising

Environmental Impact by Sequencing Cultured Dairy Products: Two

Case Studies.

Submitted manuscript (March 2005).

Paper V Berlin, J., Sonesson, U., and Tillman, A.-M. (2005). An Actor

Analysis of the Environmental Improvement Potentials in the Post-

Farm Milk Chain Using Life Cycle Assessment.

Submitted manuscript (August 2005).

Reprints of Papers I - III are printed by the kind permission of Elsevier Science

Ltd.

VI

Other publications by the author

Sonesson, U., and Thuresson*, J. (2001). Mjölkkedjans miljöpåverkan – en

miljösystemanalys av framtidscenarier av försörjningskedjan för mejeriprodukter

(Environmental Impact of the Milk Chain: An Environmental Systems Analysis

of the Supply Chain for Dairy Products, in Swedish). SIK Report 2001 No 681,

SIK: The Swedish Institute for Food and Biotechnology, Göteborg, Sweden.

* Author’s surname prior to Berlin.

Berlin, J. (2001). Life Cycle Inventory (LCI) of Semi-Hard Cheese.

SIK Report 2001 No 692, SIK: The Swedish Institute for Food and

Biotechnology, Göteborg, Sweden.

Berlin, J. (2003). Life cycle assessment (LCA): An introduction.

In: Environmentally-friendly food processing. Edited by: Mattsson, B. and

Sonesson, U., Woodhead Publishing Limited, Cambridge, England.

Berlin, J. (2005). Tänk på miljön – Ät upp maten! (Think about the

environment: Eat up your food!, in Swedish). In: Mat för Livet – om framtidens

livsmedel (Food for Life: food for the future, in Swedish), The Royal Swedish

Academy of Agriculture and Forestry (KSLA), Stockholm, Sweden.

VII

The Research Program FOOD 21

The thesis work was carried out within the FOOD 21 research program. FOOD

21 is an interdisciplinary research program funded by the Foundation for

Strategic Environmental Research (MISTRA). Natural and social scientists co-

operate in analysing the sustainability of agricultural food production from farm

to fork. The long-term goal of the program is to define optimal conditions and

to develop systems and technologies for a sustainable food chain that offers the

consumers high quality products.

VIII

Acknowledgements

Many people and organisations have assisted me during my years as a doctoral

student and I am very grateful to all. My research was carried out in the context

of the FOOD 21 research program and financed by the Swedish Foundation for

Strategic Environmental Research (MISTRA) to which I wish to express my

appreciation.

I am indebted to my supervisors, Professor Anne-Marie Tillman and Dr. Ulf

Sonesson, a most complementary team. Anne-Marie guided me skilfully into

research, environmental systems analysis, publishing articles and gave me good

advice. Ulf was a source of inspiration for my research, gave his valuable

opinions and was always available for discussions.

It is also a pleasure to acknowledge Dr. Berit Mattson and Professor Thomas

Nybrant for making good suggestions and giving support along the way and to

Professor Hans Lignert, Professor Tomas Olsson, and Dr. Karin Östergren for

valuable comments and helpful suggestions on improvement of the thesis.

Lora Sharp McQueen is thanked for revising the language of the thesis.

Several people contributed data and their knowledge to the papers appended in

this thesis. I am grateful to all, in particular Christel Cederberg, C. Cederberg

AB; Allan Nilsson and Jörgen Karlsson, Arla Foods Falkenberg; Inger Larsson,

Arla Foods; Mustafa Aoufi and Anna-Lena Östensson, Arla Foods

Östgötamejeriet; Urban Sterner, Skånemejerier; and Marcus Henningsson,

Flora Vita AB, for sharing their expertise in farming and dairy processing.

Furthermore, for invaluable assistance with information and data, I am grateful

to my colleagues in the Process and Environmental Engineering group at SIK,

IX

especially Friederike Ziegler, Britta Nilsson, Katarina Lorentzon, Anna Flysjö,

Jennifer Davis, Anna Fritzon, Tomas Angerwall and Eva Olsson.

Thanks go to all of the people at the Division of Environmental Systems

Analysis at Chalmers for always welcoming me as one of the team although my

work place has been at SIK.

I am deeply thankful to my loving and caring parents, Anita and Roger, for their

support and babysitting. My parents in law, Agneta and Bengt, are thanked for

all warm concern and babysitting. I am grateful to my sister, Josefin, her

husband, Jan, and their lovely children, Amanda and Linnéa, as well as my

sister, Ida, and her boyfriend, Anders, for always supporting me.

Finally, I thank my beloved husband and daughter, Henrik and Viola, who are

the most important persons of my life. Henrik has encouraged me and given me

all the support and love I could wish. From Viola and her infectious laughter, I

have learned the meaning of life.

Göteborg, August 2005

Johanna Berlin

X

Table of Contents

Abstract .......................................................................................................................III

List of Publications...................................................................................................... V

Other publications by the author .......................................................................VI

The Research Program FOOD 21..........................................................................VII

Acknowledgements ................................................................................................ VIII

Table of Contents ........................................................................................................ X

1 Introduction ............................................................................................................ 1

1.1 The Food Market and the Dairy Industry.................................................. 2

1.2 Aim and Objectives....................................................................................... 4

1.3 Appended Papers .......................................................................................... 5

2 The Environmental Perspective of the Dairy Chain......................................... 8

2.1 Life Cycle Assessment of Dairy Products.................................................. 8

2.2 Types of Environmental Impact Related to the Dairy Chain ................. 9

2.3 Environmental Improvements................................................................... 10

2.4 Environmental Improvements from an Actor’s Perspective................. 13

3 Methods................................................................................................................. 16

3.1 Environmental Systems Analysis Tools ................................................... 16

3.2 Scenario Techniques in LCA..................................................................... 21

3.3 Operational Analysis .................................................................................. 23

4 The Environmental Consequences of Current Trends and Options for

Improvement ........................................................................................................ 27

4.1 Environmental Impact of Future Milk Supply Chains in Sweden: A

Scenario Study ............................................................................................. 27

4.2 Life Cycle Assessment of Semi-Hard Cheese ......................................... 29

4.3 Minimising Environmental Impact by Sequencing Cultured Dairy

Products: Two Case Studies ....................................................................... 30

XI

4.4 An Actor Analysis of the Environmental Improvement Potentials in

the Post-Farm Milk Chain Using Life Cycle Assessment ...................... 34

4.5 Discussion..................................................................................................... 36

5 Methodological Contributions to Environmental Systems Analysis ............ 41

5.1 A Life Cycle Based Method to Minimise Environmental Impact of

Dairy Production through Product Sequencing ...................................... 41

5.2 An Actor Analysis of the Environmental Improvement Potentials in

the Post-Farm Milk Chain using Life Cycle Assessment ....................... 43

5.3 Discussion..................................................................................................... 44

6 Conclusions........................................................................................................... 46

7 Future Work ......................................................................................................... 47

References ................................................................................................................... 49

1

1 Introduction

A tasty meal that smells good and looks appetizing to enjoy with a loved family

and dear friends is a pleasure of life. While food gives us nutrients, proteins, fats

and carbohydrates, it also acts as a source of delight, both for taste-buds and on

a social plane.

Before we can enjoy a meal, the food has to be prepared, it is purchased from a

retailer, processed by an industry, and the raw materials are produced by

agriculture. Different modes of transportation have moved the food from one

location to another. These activities affect the environment by the use of

resources and by emissions to air, water and soil. For example, the energy used

in the life cycle of the food chain, agriculture to consumption, was estimated to

be approximately 17% of the total energy use in Sweden (Uhlin, 1997). Of this

total, agriculture accounted for 15 - 18%, industry 17 - 20%, distribution 20 -

29% and consumption 38 - 45%. Agriculture stands for approximately 50% of

all eutrophication emissions in Sweden, whereas the reminder originates mainly

from sewage and transport (SEPA, 1997a, 1997b, 1997c). To the greenhouse

gases, the food system contributes around 28% (calculation based on SEPA,

2004 and Uhlin, 1997).

The Swedish population consumes seven million tonnes of food each year, the

largest part being dairy products, which constitute 25% of the total food intake

(SEPA, 1999). The consumption of milk in Sweden is high compared with the

average EU value (111.5 kg versus 76.6 kg), but for cheese the consumption is

just below average, 17.40 kg versus 18.18 kg (Swedish Board of Agriculture,

2004a). From dairy products, Swedes receive 14% of their energy intake, 25% of

their protein, and as much as 66% of their calcium (Swedish Board of

Agriculture, 2004b). The importance of dairy products in the Swedish diet is

also shown by the Swedish National Food Administration recommendation of a

2

daily consumption of half a litre of milk or a corresponding amount of other

dairy products.

Before the objective of this thesis is stated, the current trends in the food market

and the dairy industry are described. The interrelation of the appended papers is

given as the last part of the introduction.

1.1 The Food Market and the Dairy Industry

The world market for food products is becoming more integrated and

globalised. Integration is expanding with positive economic development, rising

population and greater urbanisation (Swedish Dairy Association, 2000). This

globalisation affects activities in the life cycles of foods, i.e. agriculture,

manufacture, retailing, consumption and the transports involved.

Heavy competition between dairy manufacturers, the requirements of product

development, and the production of a wider variety of products are the forces

working to cause manufacturers to cooperate and merge. This results in larger

manufacturing companies with an international market similar to that of

retailers. Several mergers and purchases of companies have taken place in the

dairy industry. For example, in northern Europe, most dairy companies have

merged into regional or national companies, and some even into international

companies (Swedish Dairy Association, 2000). Most dairies in Europe are

owned by farmers’ co-operatives.

There is a trend in the dairy industry towards production in a few large

specialised dairies. This specialisation can mean that one dairy produces mainly

consumer milk, a second cultured products and a third cheese. This leads to

more and longer transports from the dairy to the retailer. Fewer dairies and the

dairy farmers’ similar movement towards fewer farms also imply longer distance

of transports from the farm to the dairy.

3

The milk chain is a pushing system which has implications for the product

portfolio: the milk produced at the farms must be processed promptly into

products at the dairy. Since changing the volume of milk production at a dairy

farm is a slow process, it is not possible to adjust the amount of incoming milk to

rapidly changing market requirements, nor can milk be stored for long periods

of time. As the volume of incoming milk to the dairy cannot easily be adjusted,

the mix of outgoing products is changed instead, i.e. when the market

requirements change, the dairy industry must shift to other products that meet

the new requirements. This drives an increasing diversity of products. The

companies also contribute to diversity by releasing new products to generate a

greater demand for their output.

There has been a trend in the past 20 years towards increased consumption of

cultured products and cheese, with a decrease in consumption of drinking milk

products and butter. In Sweden, cultured milk and cream and yoghurt showed

an increase of 18% from 1985 to 2001. The increase in cheese consumption was

13% from 1985 to 2001, particularly soft cheese. Reductions noted in consumer

milk consumption were 26% and in butter consumption 37% from 1986 to 2001

(Swedish Board of Agriculture, 2004b).

4

1.2 Aim and Objectives

The aim of this work is two-fold. The first aim is to increase knowledge of the

environmental impact of the post-farm dairy chain and to assess potential

improvements. The second aim is to contribute to development of methodology

for environmental systems analysis.

Specific objectives related to the first aim are:

▬ assessment of the environmental consequences of ongoing changes in

society, which influence the dairy product chain, and

▬ generation of improvement options and assessment of their

environmental consequences.

Specific objectives related to methodology are:

▬ to develop a method to design an environmentally preferable, or even

best, sequence for products that are produced consecutively with the

same equipment, and

▬ to develop a method of identifying the activity, for each actor in the post-

farm chain, which offers the greatest environmental improvement in a life

cycle perspective.

In the work covered by the five papers, the goals dealt with are as follows:

• to develop potential future scenarios for the milk supply chain;

• to identify the key environmental issues for the milk supply chain;

• to acquire environmental data for the life cycle of cheese;

• to determine the key environmental issue in the life cycle of cheese;

• to design a sequence, for a given set of products, which minimises milk

waste in a multi-product manufacture;

• to investigate the environmental role of the frequency of each product in

a sequence; and

• to identify the actions, by the dairy, retailer and household, which offer

the most environmental improvement in a life cycle perspective.

5

1.3 Appended Papers

The thesis is based on five papers, the work for which was conducted from a top

down perspective according to the systems analysis approach. Figure 1 shows

how the papers are related to each other.

Figure 1. Interrelation of the five appended papers.

Paper I, a scenario study, gives an overview of the environmental impact of the

dairy sector today and of potential changes in the sector according to present

trends. During the work with the paper, stakeholders including representatives

from a dairy company, a major food retail company, a dairy equipment supplier,

an environmental consultant, and researchers working in related areas were

interviewed. After an initial round of visits to all those involved, the research

group and the persons interviewed attended a seminar at which the scenarios for

study were broadly sketched; thereafter, a more detailed description of each

scenario was prepared. The preliminary results from simulations using these

scenarios were then presented to the same group of people at a second seminar

where we made modifications. Finally, the scenarios were given their final form

Environmental Impact from Future Milk Supply Chains in Sweden: A Scenario Study (Paper I)

Environmental Life Cycle Assessment (LCA) of Swedish Semi-Hard

Cheese (Paper II)

A Life Cycle Based Dairy Model to Minimise Environmental Impact by

Product Sequencing (Paper III)

Minimising Environmental Impact by Sequencing Cultured Dairy

Products: Two Case Studies (Paper IV)

An Actor Analysis of the Environmental Improvement Potentials in the Post-Farm Milk Chain Using Life Cycle Assessment

(Paper V)

6

which included: variation of products, both small and large scale dairies,

differences in modes of transport, different kinds of retailers, and a diversity of

packaging volumes. A model based on material flow and substance flow

accounting, together with the impact assessment part of life cycle assessment

(LCA), was constructed to assess the scenarios. The knowledge gained about

the dairy chain and current trends then constituted the basis for selecting

specified subjects to be further investigated in the subsequent work.

A lack of good quality, published, environmental data on cheese production and

the fact that a major quantity of the milk produced will end up as cheese

(approximately 10 kg milk is required to make 1 kg of cheese) together with the

ongoing increase in cheese consumption (13% from 1985 - 2001, Swedish Board

of Agriculture, 2004b) were the reasons for carrying out a life cycle assessment

of cheese.

That dairy products have become more and more diversified during recent years

is a fact. Product diversity was hard to include in the scenario study (Paper I) as

there was no information to be found about its environmental implications.

When diversity was discussed in the reference group, it emerged that it has been

dealt with from economic and technical viewpoints, but there were few studies

from an environmental standpoint. Hence, research was initiated on designing a

method that would minimise environmental impact by product sequencing at

the dairy (Paper III). The production of cultured products is mostly affected by

the greater product diversity when compared with drinking milk and cheese as

their batch volumes are much larger. A method for sequencing cultured

products was developed. A heuristic solution, which was designed intuitively

and based on production rules, was worked out for yoghurt production. To

determine whether the heuristic solution gave the best possible sequence from

an environmental perspective, an optimisation solution was also made. This

detailed scheduling model was successfully included in a life cycle assessment of

7

the production schedule at two dairies, Paper IV. The sequenced products were

yoghurt, sour cream, cold sauce and crème fraiche, all with multiple flavours.

During the work with the case studies, the role of frequency of each product to

be sequenced attracted attention. Technical scenarios with differing frequencies

were evaluated with life cycle assessment methodology in order to improve the

environmental impact.

Improvement assessment was also the topic of Paper V, but this time from an

actor perspective. A literature search did not reveal any publication dealing with

the measures taken by actors in the post-farm dairy chain from a life cycle

perspective. Hence, Paper V searched for the potential action, by the dairy,

retailer and household, that offers the most environmental improvement of the

product life cycle. The actions investigated were improved energy efficiency,

better transport patterns, reduced milk and product losses and organic labelling.

The three products considered were milk, yoghurt and cheese. Literature

studies and interviews with stakeholders to estimate improvement potentials

were used in combination with LCA methodology.

8

2 The Environmental Perspective of the Dairy Chain

A life cycle environmental perspective is applied in this work. First, previously

published studies of the dairy chain using life cycle assessment methodology are

given here. Next, the types of environmental impact related to the dairy chain

are discussed, followed by a section about how reductions of these impacts are

treated in the literature. The last part examines how actors can contribute to

environmental improvements.

2.1 Life Cycle Assessment of Dairy Products

As with most food items, milk products originate from agriculture. The dairy

farm produces the milk, and it is collected by a truck which delivers it to the

dairy. At the dairy the milk is processed into a variety of dairy products and

packaged for the consumer. After that they are delivered to the retailer where

the products are displayed for consumers on a refrigerator shelf or in a cold

room. A dairy item purchased by a consumer is transported to the household

and stored in the refrigerator before the final consumption. Each of these

activities in the milk chain causes environmental impact. The impacts of dairy

products have been identified and evaluated in several studies using life cycle

assessment (LCA) methodology. Nilsson and Lorentzon (1999) studied the

environmental consequences of processing milk. Høgaas Eide (2002b) made an

LCA of milk in which three milk-producing dairies were investigated. A

screening LCA of milk powder was undertaken by Blonk et al. (1997).

Lorentzon et al. (1997) studied the environmental effects of coffee cream, from

processing at the dairy to the purchaser. An LCA of the production of cultured

milk was made by Grøtan (1996), while butter was the subject of the LCA pilot

study at an Italian dairy company by Masoni et al. (1998). A soft cheese, a

Camembert, was examined in an LCA by Bernhard and Moos (1998). Although

the system boundaries differed in these publications, a consistent finding of

those which included a farming component was that agriculture had by far the

9

greatest environmental impact for most parameters. The ranking of the

contributions of the other life cycle phases to the environmental impact is not as

clear. The answer differs depending on the product and the environmental

impact category considered. However, the dairy, the production of packaging,

and the transport between retailer and household seem to make a higher

contribution than the other transports, the retailer and the household.

2.2 Types of Environmental Impact Related to the Dairy Chain

Agriculture contributes to global warming by emissions of methane and nitrous

oxide and to a lesser extent through emission of CO2 originating from the use of

fossil fuels. Livestock is the source of most of the methane emissions partly

because of ruminants’ enteric fermentation and partly due to manure

management with methane production under anaerobic conditions. Nitrous

oxide is released as a result of nitrification and de-nitrification processes in the

soil, as well as nitrogen transformation in manure. Emissions of nitrogen

pollutants are also the source of both eutrophication and acidification. The

release of ammonia is linked to the farmyard manure. Ammonia is not

acidifying in a chemical sense, but it has a strong acidifying effect as a result of

nitrification in the soil. Nitrate leaches from the arable land. Dairy farming

makes heavy demands of the land for example by soil erosion and compaction.

On the other hand, grazing ruminants also preserve valuable biotopes.

Concerning the use of resources, phosphorus should be highlighted, since it is

used not only as fertiliser but also as a mineral feed additive (Cederberg, 2002).

During processing at the dairy, separation, homogenisation and pasteurization

use most energy (Høgaas Eide and Ohlsson, 1998, Nilsson and Lorentzon,

1999). The cleaning operations have also been identified as a major source of

environmental impact (Lorentzon et al., 1997). Water, cleaning agents

(commonly used are nitric acid and sodium hydroxide) and energy are required.

The Cleaning in Place (CIP) system is usually used in dairies. This means that

10

rinsing water and cleaning agents are circulated through tanks, pipes and

process lines without dismantling the equipment. Effluents consist of milk

residues and water containing the cleaning agents. How much of the effluent

reaches the environment depends on the sewage treatment.

The production of the package as well as the waste management of packaging is

considered critical to the environmental impact, especially for products with a

low degree of processing. For dairy products, consumer milk is the least

processed, next are cultured products, and the most processed is cheese. The

manufacture of packaging as well as its distribution was shown to have a

considerable impact on energy use (17% of the total life cycle) and global

warming potential (18%) in a study of milk by Høgaas Eide (2002a). The

package was a one litre paperboard carton. The waste management of the

carton was the main contributor to eco-toxicity (59% of the total life cycle). The

design of the package is also highly relevant for the product loss in the consumer

phase (Johansson, 2002).

At the retailer and in the household, the electricity needed to keep the products

cold causes environmental impact. The environmental impact depends on the

energy mix used for producing the electricity. The Swedish average electricity

mix is made up of approximately 45 % each of hydroelectric- and nuclear

power, the remainder being produced from oil and combined heat and power

plants using bio fuel (Swedish Energy Agency, 2004). Hydroelectric power

affects biodiversity and landscape aesthetics and nuclear power cause emissions

of radioactive substances and radioactive waste.

2.3 Environmental Improvements

Within the food sector measures to decrease environmental impact are

continuously applied. Examples include improved plant nutrient balances on

farms, more energy efficient processes, reduction of material in packaging,

11

better logistic solutions, and environmental requirements for procurement.

Action for environmental improvement is traditionally taken at each part of the

food chain.

Measures to reduce environmental load in the agricultural phase are important,

as all LCAs of dairy products have identified farming as the dominant

contributor to the environmental impacts (see Section 2.1). Different types of

farming practices have been investigated in several studies. A review of the

environmental impact assessment of conventional and organic milk production

was made by de Boer (2003). Three studies of the differing agriculture practices

in northern Europe, i.e. south western Sweden, the Netherlands and southern

Germany, were reviewed. Cederberg and Mattsson (2000) assessed organic and

conventional farming practices in Sweden, and the Dutch study was carried out

by Iepema and Pijnenburg (2001). Both of these found that organic milk

production is a way to reduce pesticide use and mineral surplus. However, this

type of farming requires more grazing land than conventional farming. For

Sweden this was positive in that it promotes the domestic goals of preserving

biodiversity. However in the Netherlands, land is a scarce resource, which

makes greater land use a negative impact. Haas et al. (2001) who published the

German study came to the conclusion that, by renouncing mineral nitrogen

fertilizer, organic farming reduced the energy use and the global warming

potential in comparison with conventional farming. All three studies were based

on comparisons of experimental farms. The conclusion by de Boer (2003) was

that differences between production systems require assessments of a large

number of farms for each production system.

Another study of quantified improvement action in agriculture, made by

Hospido et al. (2003), dealt with Galician (Spanish) milk production. The

actions investigated were the reduction of milk losses during milking, a changed

feed composition with more maize and less silage, and the implementation of

12

treatment systems for water and air emissions. Moreover, a measure introduced

to improve dairy herds is the reduction of mastitis. Mastitis is an inflammatory

reaction of udder tissue to bacterial, chemical, thermal or mechanical injury.

The environmental impact of mastitis was assessed with LCA methodology by

Hospido and Sonesson (2005). A standard scenario for the incidence of mastitis

(present-day reality in Galicia) was compared with an improved one. A

reduction in the incidence of mastitis implies that the same amount of milk

would be produced in a shorter period of time or by fewer cows, hence the

impact on the environment would be lower. For example, the greenhouse gas

emissions from the agriculture sector of Spain could be reduced by 0.56% if

measures were taken to reduce the incidence of mastitis.

At the dairy, measures to lower the environmental impact include using less

energy, cleaning agents and water, decreasing the wastage of milk and other

products, thus raising the yield. A systems analysis of the energy used at two

dairies was published by Karlsson et al. (2004). Each step of the process and

each item of equipment was assessed. Specific actions to save energy were

identified and quantified with time perspectives from one to more than five

years; they concluded that the energy use could be decreased by 8% if all of the

actions were realised. Høgaas Eide et al. (2003) assessed four Cleaning in Place

(CIP) methods using life cycle assessment methodology. Production of cleaning

agents, transport, actual cleaning at the dairy and waste management of the

containers were included. The actual cleaning at the dairy was the most

important part of the life cycle. The CIP methods, enzyme-based cleaning and

one-phase alkaline cleaning, both using small volumes and low temperatures,

were found to be the best alternatives for the impacts of energy use, global

warming, acidification, eutrophication and photo-oxidant formation. A waste-

optimised product scheduling could decrease wastage of milk and products and

in that way increase the yield. A methodology for incorporating ecological

considerations into the optimization of design and scheduling of batch processes

13

was conducted by Stefanis et al. (1997); this included a case study of a cheese-

making dairy. The optimizations were based on both process economics and

environmental impact. In a theoretical study, Grau et al. (1995) introduced

optimization of process-sequence dependent changeover waste (as an

environmental issue) in product scheduling of a batch production unit.

Høgaas Eide (2002a) reviewed eleven LCAs of milk packaging and concluded

that a light-weight recyclable package, with properties that did not increase the

loss of product, was the best milk packaging alternative. Improvement options

for the retailer and in the household include more energy efficient cold storage

and other action to decrease product losses. An analysis of the ways to reduce

the energy requirements of refrigerator cabinets at the retailer was made by

Axell (2002). A test of 119 household refrigerators was made by Sonesson et al.

(2003). The difference was as much as 11.27 MJ/(per litre and year) between the

refrigerator using the most energy and the one using the least. Studies of

improvement actions to reduce the losses of dairy products in the household are

rare. There are different kinds of losses in the household, such as product left in

the container when the consumer considers it is empty, losses during

preparation, food left on the plate or in the glass, or thrown in the bin or the

sink when it has spoiled or passed shelf life. Each of these losses could be

decreased. The importance of the design of the packaging for food losses was

tested by Johansson (2002). In a comparison of packages for yoghurt, the cup

shape had 3.4% yoghurt left when considered empty, whereas the gable top had

8.7%. Losses of dairy products after mealtimes and storage were studied by

Sonesson et al. (2005) but they did not include improvement actions.

2.4 Environmental Improvements from an Actor’s Perspective

A range of actions is available to decrease the environmental impact. The best

choice for each actor may not be the same for all who are involved in the same

consumption chain because their domain of influence differs. For example,

14

although the consumer is not able to influence the production schedule at the

dairy, there is still a choice between organic or conventional milk during

purchasing. Actions taken by one person may lead to substantial improvements

in phases of the life cycle controlled by other people. Environmental studies of

the food chain from an actor perspective are rare in the literature. Jungbluth et

al. (2000) published one of the few and pointed out the consumer as the actor

with the greatest potential to influence the food chain in environmental matters.

They found that the consumer had the widest range of choice to make decisions

that reduce the environmental impact. The method applied was reviewing

published LCA studies. Five single aspects of decisions were identified: type of

agricultural practice, origin, packaging material, type of preservation and

consumption. These decisions were then assessed in simplified LCAs of meat

and vegetables. The most important options for a reduction of environmental

impact were found to be refusal of air-transported products, a preference for

organic foods and a reduction in meat consumption.

Another important decision made by the consumer is the choice between foods.

An environmental comparison of four meals was made by Carlsson-Kanyama

(1998). Although the study did not include an actor analysis, it is relevant for

this topic in that it is a study of decisions made by one actor in the food chain.

This comparison concluded that a meal composed of tomatoes, rice and pork

has nine times higher impact on climate change emissions than a meal made

from potatoes, carrots and dry peas. A subsequent investigation by Carlsson-

Kanyama et al. (2003) shows that contrasting diets with similar energy content

can vary in energy input by a factor of four, from 13 to 51 MJ. They also

concluded that the least energy consuming diets, which are far from the Swedish

average, are not in line with current trends.

In another study of the influence of decisions taken by one actor in the food

chain, Lindgren and Elmquist (2005) examined the environmental and

15

economic impacts of decision making at an arable farm. Variations in prices,

subsidies, the farmer’s attitudes about environmental concerns, and the farmer’s

skill in making production allocation choices were studied. With regard to

economic performance, either organic farming or a conventional cultivation

with a large amount of pesticides and fertilizers offered the most profit. The

former benefited from higher subsides and selling prices, the latter from large

yields. Regarding environmental impacts, the result depended on the impact

category studied. To obtain a low contribution to eutrophication and

acidification, conventional farming was preferred, due to ammonia emissions

during slurry spreading. Nevertheless, to reduce global warming, the organic

alternative was preferable because no mineral fertilizer was used.

16

3 Methods

This thesis is based on five papers, the work for which was conducted by various

methods. The aim of each study determined the choice of methods and system

boundaries used during modelling. The methods used were: environmental

systems analysis methods of various types, mostly life cycle based; a scenario

technique; quantitative problem techniques; interviews and seminars with actors

in the dairy chain; and visits to dairies. A general description of the methods

follows with specific comments about how they were used in the work.

3.1 Environmental Systems Analysis Tools

Environmental systems analysis includes several tools which can be categorised

as flow models, monetary models, procedural methods and risk assessment.

Examples of tools based on physical flows are life cycle assessment, material

flow accounting and substance flow accounting. Cost-benefit analysis facilitates

assessing total costs, including environmental costs, and benefits from a planned

project. In design for the environment, a wide range of procedural methods are

used, in an effort to include the environmental dimensions into the design

process. Risk assessment is a broad term that covers several types of

assessments, to deal with human health or environmental aspects. The risk can

also vary from diffuse to specific and can be associated with customary usage or

accidents. Frameworks for comparing differing approaches was devised by

Baumann and Cowell (1999); they were further developed in Wrisberg et al.

(2002) and Finnveden and Moberg (2005). Baumann and Cowell (1999)

emphasize the importance of practical integration of existing approaches for a

variety of applications, rather than developing new tools, and Wrisberg et al.

(2002) agreed. Furthermore, Finnveden and Moberg (2005) came to the

conclusion that, depending on the objects the tools focus on, different tools

cannot easily replace each other. In the following the tools used in the papers

17

included in this thesis are briefly outlined; life cycle assessment, material flow

accounting and substance flow accounting.

3.1.1 Life Cycle Assessment

Life cycle assessment (LCA) is used in all of the appended papers. In Paper I,

the impact assessment element of LCA methodology was chosen for the

interpretation of the result. Paper II is a descriptive LCA of cheese. An LCA

study is either descriptive or change-oriented. A descriptive (attributional or

accounting) study describes a system as it actually is. A change-orientated

(consequential or effect-oriented) study analyses the consequence of a choice.

In Paper III, a sequencing method is worked out and it is shown that it may be

linked to LCA. To evaluate the scenarios of different frequencies of production

in a sequence, LCA was linked to the sequencing method (Paper IV). The work

in Paper V started with descriptive LCAs carried out for milk, yoghurt and

cheese. Then these LCAs were changed to show the estimated improvement

measure of each actor. A comparison of the changed LCAs revealed the action

that made the greatest difference from an environmental point of view for each

actor in the chain. A brief description of LCA in general with specific examples

from the papers follows.

Life cycle assessment is a tool for evaluating the environmental impact

associated with a product, process or activity during its life cycle. This is

accomplished by identifying and quantitatively or qualitatively describing its

requirements for energy and materials, and the emissions and waste released to

the environment. The life cycle is included in the assessment, which means that

the product under study is followed from the initial extraction and processing of

raw materials through manufacturing, distribution, and use, to final disposal,

including the transports involved. Besides identifying and quantifying the

environmental impact of the product or activity, LCA also identifies what

activities in the product life cycle contribute the most to this impact. An LCA is

18

an ISO standardised tool (ISO, 1997, 1998, 2000a, 2000b) and included in the

standard is a working procedure, illustrated in Figure 2 and described below.

Figure 2. Working procedure for an LCA. The unbroken line indicates the order

of procedural steps and the dotted lines show iteration. (Baumann and Tillman,

2004, and ISO, 1997)

An LCA starts with an explicit statement of the goal and scope of the study, the

functional unit and allocation methods used, the system boundaries, the

assumptions and limitations, and the impact categories chosen. The functional

unit is quantitative and corresponds to a reference flow to which all flows in the

LCA are related. Allocation is the method used to partition the environmental

load of a process when several products or functions share the same process.

The allocations used in the papers are mostly based on economic partitioning,

that is, on the value of the items produced as reflected in their relative prices or

the gross sales value. Economic allocation is commonly used in relation to food

products. Various system boundaries can be chosen depending on the purpose

of the study. When the whole system is assessed, from resource exploration to

the waste management, the study is designated a cradle to grave study.

Sometimes only parts of the life cycle are of interest: in a cradle to gate analysis,

resource exploration and production are included but not use and waste

Goal & Scope Definition

Inventory Analysis

Impact Assessment

Classification Characterisation

Normalisation Weighting

Interpretation

19

management. Another example is gate to gate analysis in which neither the

resource exploration nor waste management are included; sometimes the use

phase is omitted as well. The goals and scope, excluding the allocation, used in

the appended papers, are summarised and listed in Table 1.

In the inventory analysis a flow model of the technical system is constructed

using data on inputs and outputs, i.e. resources, energy requirements, emissions

to air and water, and waste generation for all activities within the system

boundaries. The inventory analysis is followed by impact assessment, in which

the data are interpreted in terms of their environmental impact. In the

classification stage, the inventory parameters are sorted and assigned to specific

impact categories. The next step is characterisation, where inventory parameters

are multiplied by equivalency factors for each impact category. Thereafter all

parameters included in each impact category are added to obtain the total for

that category. Examples of environmental impact categories are acidification,

eutrophication and global warming.

For many LCAs, the analysis is concluded by a characterisation, which is the

case for all LCAs included in the appended papers. However, some analyses

involve the further step of normalisation, in which the results of the impact

categories are compared with the total impact in the geographical region

relevant for the study. The size of the region depends on the nature of the

impact; some impacts are global while others are regional or even local. During

weighting, the kinds of environmental impacts are weighted against each other

to find an overall value for the total environmental impact. For the purpose of

the papers in this thesis, normalisation and weighting were regarded as

unnecessary.

20

Table 1. An overview of goals and scope in the LCA approach in the appended

papers.

Goal Functional unit System

boundary

Environmental

impact

Milk chain

Paper I

Assess the environmental

impact of future supply

chains for dairy products.

The total

amount of milk

from the farms

in a region

Gate to grave:

from incoming

dairy transport

to household

consumption

Energy, global

warming,

eutrophication,

acidification and

POCP

LCA of

Cheese

Paper II

Acquire data and identify

key issues in the life cycle

of cheese.

1 kg semi-hard

cheese at the

consumer table

Cradle to gate:

from dairy farm

to consumer

table

Resources,

energy,

eutrophication,

acidification,

global warming,

POCP, eco and

human toxicities

Sequence

model

Paper III

Construct a sequence

model to minimise milk

waste. Obtain the impact

of a production sequence.

One processing

sequence of

yoghurt

products

Cradle to gate:

from dairy farm

to dairy

delivery gate

Eutrophication,

acidification,

global warming

and POCP

Cultured

product

sequencing

Paper IV

Obtain the impact by

production of a sequence

at two dairies. Investigate

the environmental

implications of the

frequency of each product

produced.

One processing

sequence of

yoghurt, sour

cream, cold

sauce and

crème fraiche

Cradle to gate:

from dairy farm

to dairy

delivery gate

Eutrophication,

acidification,

global warming

and POCP

Most

effective

actor action

Paper V

Identify the actions taken

by the dairy, retailer and

household, that give the

most environmental

improvements in a life

cycle perspective.

• 1 kg milk

consumed

• 1 kg yoghurt

consumed

• 1 kg cheese

consumed

Cradle to grave:

from dairy farm

to household

consumption

Energy,

eutrophication,

global warming

and POCP

POCP is photochemical ozone creation potentials

21

3.1.2 Material Flow Accounting and Substance Flow Accounting

Material flow accounting (MFA) describes all in- and outflows and

accumulation of a material, substance or element in a geographic area for a

given period of time (Udo de Haes et al. 1997). Depending on the type of

material studied, a further distinction of MFA is often applied. Bulk-material

flow analysis studies flows of materials, such as wood, iron or plastics, in a given

region. Flows of substances such as nitrogen compounds and single elements

such as cadmium or lead within a region are traced in a substance flow

accounting (SFA) (Udo de Haes et al. 1997). Van der Voet et al. (1995) state

that one of the aims of SFA is to obtain an overview of the economic and

environmental flows in a specific geographical region. Cederberg (1999), for

example, quantified the flows of nitrogen, phosphorus and potassium connected

with the production and consumption of food in a Swedish district. Both MFA

and SFA were used in Paper I, together with the impact assessment element of

LCA. The flow under study was milk in a region of central Sweden. Together

with the accounting for the resources and energy consumption, this is the part

that is based on MFA. However, accounting for the in- and outflows of all the

emissions that occurred in each step of the milk product system as well as taking

into account the protein content can be considered in an SFA. A life cycle

perspective was used in the study.

3.2 Scenario Techniques in LCA

In the context of LCA the SETAC Europe working group on scenario

development defined a scenario as a description of a possible future situation

relevant for specific LCA applications, based on specific assumptions about the

future and, when relevant, a description of a path from the present to the future

(Weidema et al., 2004, Pesonen et al., 2000). They distinguished three types of

scenario application in LCA: technology, environment, and valuation. In this

thesis most of the scenarios used can be categorised as the technology type,

which concern the technosphere or more specifically the product system, except

22

for those used in Paper I. They were based on changes in societal developments

and consumer behaviour, which in turn led to modified product systems.

According to van der Voet et al. (1995), changes in society, which affect

substance flow, can be linked to an SFA study. Examples of this are the SFA

studies connected to scenario analysis, presented by Sonesson et al. (1997) and

Björklund et al. (2000). Both of these dealt with the environmental

consequences of scenarios for waste management in Swedish cities.

3.2.1 What-if and Cornerstone Scenarios

According to Weidema et al. (2004) and Pesonen et al. (2000) there are two

principal approaches to scenario development in LCA studies: what-if scenarios

and cornerstone scenarios. The what-if approach is the most widely used of the

two and has a shorter time perspective. The environmental impact of specific

changes is compared or tested. What-if scenarios often result in quantitative

comparisons of the options selected. In a cornerstone approach scenarios are

chosen to give an overall view of the subject of study. They mark the outer

limits of possible developments in order to ensure that the differences between

them stand out clearly and to facilitate the identification of key differences.

What-if scenarios were used both in Paper IV (Cultured product sequencing)

and Paper V (Actors’ action selection). In Paper IV case studies were carried

out for several technical scenarios. Three scenarios for each dairy, with differing

frequencies of the products, were devised for the sequencing. To vary the

product frequency means to vary how often a given product was made weekly.

The frequencies of the products chosen for the scenarios were: the frequency

currently used for each product (2 - 5 times per week); twice a week for each

product; and, in the last scenario, 1 - 2 times per week for each one according to

their shelf life. The scenarios were designated: Reference, Goal and Future. The

Reference scenario reflected the current situation. The Goal scenario was

23

assumed to be achievable for most dairies within a reasonable time. The Future

scenario was believed to be attainable in the future.

In Paper V improvement measures were environmentally assessed and

compared. Each action taken by each actor can be viewed as a what-if scenario,

although it was not termed so in the paper. The actions investigated were

improved energy efficiency, better transport patterns, reduced milk and product

losses and organic labelling. These changes could be made by the dairy, the

retailer and the household, although each actor could undertake only some of

them. The time perspective was five years from now.

The scenario technique used in Paper I (the milk chain study) mirrored possible

developments in the milk supply chain. The scenarios were defined with ideas

from the reference group discussions (see Section 1.3) but with simplifications to

make them feasible. The selections were made to give an overall view of the

milk chain and thus represent the most extreme developments in society and

consumer behaviour, similar to the cornerstone approach. The reference

scenario reflects the milk chain as it was structured in 1999. A version called

Large Scale assumes a shift towards larger units within both industry and among

retailers. The Splendid Times version resembles the Large Scale but with the

difference that there has been greater economic growth. An economic recession

with a decrease in the use of cars was included in the Harsh Times version. The

last scenario simulated was the Green IT Wave which assumes a less

materialistic lifestyle. Each variation, except the reference scenario, had a time

perspective of 20 years in the future.

3.3 Operational Analysis

Operational analysis is a group of quantitative techniques for solving systems

analysis problems. Included in the category are optimisation, linear

programming, dynamic programming, and queue theory (Gustafsson et al.,

24

1982). In Paper III a heuristic procedure (an intuitively designed procedure) was

worked out to achieve the environmentally preferred production sequence of

yoghurt products. The heuristic solution was validated with an optimised one.

Both of the solutions are described below.

3.3.1 The Heuristic Solution for a Product Sequence

Heuristic procedures are intuitively designed and can give a good approximate

solution. Although they cannot be guaranteed to give an optimal solution they

are often used for very large problems (Hillier and Lieberman, 1995). The

heuristic procedures used in Paper III were based on rules used in a yoghurt

producing dairy. More specifically, the rules were based on the characteristics of

each product, which determined the choice of technique selected for a product

change. The techniques were cleaning, rinsing and the pushing principle.

Cleaning causes the most waste, use of cleaning agents and water, followed by

rinsing which uses only water; the pushing principle causes the least waste and

does not use cleaning agents or water. Therefore the best schedule uses the

pushing principle the most, while rinsing and cleaning are used as seldom as

possible.

The first step was to make a matrix of all of the products and list their individual

characteristics (base, presence of rhubarb and vanilla, allergenic potential and

intensity in colour). Then the sorting procedure starts with grouping according

to the yoghurt base. Within each base, products containing rhubarb and vanilla

were placed last. Products with allergic substances were next to the last. Finally,

the rest of the products within the base group were sorted by increasing colour,

pale ones first and the dark ones last. This sorting procedure is a solution to the

production schedule. However, there is no guarantee that this is the optimal

solution, because the sorting is done according to processing rules used during

manufacturing, and there is not a test of all possible solutions to find the best

one for the schedule.

25

3.3.2 Finding a Waste Minimised Sequence for a “Travelling Salesman

Problem”

Finding the optimal product sequencing solution involves searching through all

possible combinations of the manufacturing order of the set of products to be

sequenced. Our problem had similarities to the “travelling salesman problem”

(TSP): given a set of N cities, find the shortest route connecting them all, with

no city visited twice (Sedgewick, 1988). For our problem, the cities were

interpreted as yoghurt types and the routes connecting them were weighted

according to the waste volume caused by a product change. The waste volume

was determined by the product change technique (cleaning, rinsing, pushing

principle), which in turn was governed by the processing rules. This problem

formulation gave rise to a weighted, directed TSP. Moreover, the TSP graph was

complete since there is a route between any two products in the graph. A large

TSP is insoluble in practice, as the number of solutions that must be checked

grows in proportion to the faculty of the cities involved (N! = 1 · 2 · 3 ··· N). The

optimisation presented in Paper III was made to validate the heuristic solution

for the waste minimised sequence, for as large a number of products as possible

within a reasonable time. For more information about TSP, see Sedgewick

(1988).

For the optimisation in Paper III the problem was: Given a mix of products, find

the production sequence that causes the least waste. The waste that occurs

during a product change depends on the properties of the two products. The

problem has as many as N! solutions for the schedule, where N is the total

number of products in the sequence. First an exhaustive search was made to

check all possible solutions for the scheduling of products. The result of this was

not satisfactory; as it took 89 minutes to check the number of solutions (12! =

479 001 600) for 12 products on a standard laptop. To enable scheduling more

products, it was decided to reduce the number of solutions checked without

sacrificing optimality. The sum of the waste, x, for the first sequence was

26

calculated. For the following searches, it was fruitless to continue any sequence

for which the summed waste was greater than x, therefore these ones were

removed. After this 14 products could be sequenced with minimum waste in 140

minutes.

To improve the optimisation even more, a method known as branch-and-bound

was chosen (Sedgewick, 1988). For a given partial product sequence, a lower

bound of the total waste of all product sequences, which started with that

particular partial product sequence, was computed. If the waste of the best

sequence found so far was less than this bound, then all of those sequences

could be disregarded and did not need to be searched. The algorithm was

applied recursively until all possibilities were searched. In this way the workload

was significantly reduced, since the bound could be computed very efficiently.

The branch-and-bound technique reduced the number of solutions dramatically.

By using both of the techniques described to limit the full searches, we were

able to make a schedule of 21 products within a reasonable time (30 minutes).

With 21 products 5.1 · 1019 sequences were tested. The best of those was the

solution to our problem. Note that the algorithm is still guaranteed to find the

waste minimised sequence (Sedgewick, 1988).

27

4 The Environmental Consequences of Current Trends and

Options for Improvement

Current trends in society and industry have consequences for the milk chain and

its environmental impact. Assessment of these is one of the aims of this work

and was dealt with in three of the appended papers (I, II and IV). When

information gathered reveals a trend of negative impact, it is time to find a way

to improve the situation. Improvement possibilities, another objective of the

thesis, were dealt with in all the appended papers, in particular Papers IV and V.

This chapter gives an overview of the findings from each of the papers. A

discussion about the findings in relation to trends and improvement options

concludes the section.

4.1 Environmental Impact of Future Milk Supply Chains in Sweden: A

Scenario Study

The first paper aimed to form an overview of some potential developments of

the supply chain for dairy products in a specific region of Sweden, and the

effects these would have on of the environment. The milk supply chain under

study is located in the central part of Sweden, roughly an east-west line 100 km

north of Stockholm and southward, excluding the southernmost region, Skåne.

The milk flow in this region was investigated with the tools MFA and SFA and,

to some extent, LCA (impact assessment). The life cycle perspective used in the

study included resource use for transporting whole milk from farms to dairies,

processing in dairies, distribution to retailers, retail stores, transport to

households and finally storage in homes. The environmental impact of energy

production, manufacture of packaging material, waste management and sewage

treatment caused by the milk chain was also integrated. The agriculture was not

included. The major dairy products included were drinking milk, cream, butter,

cultured products (e.g. yoghurt) and cheese.

28

Five scenarios were worked out to mirror possible developments in the milk

supply chain, see Section 3.2.1. The total volume of milk from the farms in the

area was constant in all scenarios; the same amount of milk was also leaving the

system but in different combinations of products and losses. The most

preferable scenario from an environmental view for most impact categories was

the one designated Harsh Times, while the least preferable scenario was

Splendid Times. These two were the extremes of the economic growth in

society. In Harsh Times the price was the most important factor, and in Splendid

Times service was essential. This was shown by the products consumed, the kind

of retailers used, how to get to the retailer, and the size and material used for

packaging. In Harsh times drinking milk is the product most consumed.

Electronic shopping is frequently used or the neighbourhood retailer, as fewer

people can afford a car. The products are produced in large cardboard packages

to reduce the price of the products. In Splendid Times the amount of cheese and

cultured products consumed were increased at the expense of drinking milk.

Travelling by car to distant retailers or specialised shops is the usual way of

purchasing food. Many small bottles and packages of products with different

flavours are preferred. The bottles and packages are made of polyethylene

terephthalate (PET) and high-density polyethylene (HDPE).

Measures could be taken to improve all five scenarios. The production of

packaging materials, the waste management and the transports had the greatest

impact on the environment and resource use in all five. For transports it was the

part between retailers and households that contributed the most. Consequently,

improvement action in these areas would decrease the environmental impact.

The industrial part was important when considering resource use, such as the

net energy turnover, but had a minor impact on the effect categories included.

29

4.2 Life Cycle Assessment of Semi-Hard Cheese

The purpose of the cheese study was to identify the environmental

consequences of Swedish cheese production and the most environmentally

important activities within its life cycle. LCA fulfilled the requirements of this

objective and was found to be the appropriate method for the study. The focus

of the investigation was on the cheesemaking dairy. One of the most popular

semi-hard cheeses in Sweden was selected, Hushållsost. The system studied

covered the extraction and production of the ingredients required for

cheesemaking, as well as retailers, households, waste management and the

transports involved.

The main outcome was that milk production at the farm was the activity in the

life cycle that contributed most to the environmental impact categories included.

The result agrees with other LCAs of dairy products (see Section 2.1). The

agricultural activities accounted for as much as 93% to 99%, depending on

impact category, of the total life cycle contribution. The contribution from the

cheesemaking dairy was 0.5% to 4% depending on impact category. Apart from

the agriculture and the cheesemaking dairy, the retailers and the production of

plastic were also contributors to the environmental impact of Hushållsost.

To make substantial improvements in the environmental performance of cheese

production, it is necessary to address the activities that contribute the most to

the environmental impact. Improving farming practices with the environment in

mind could substantially raise the performance of the system studied. However,

farming is beyond the scope of this thesis, and therefore I refer to Cederberg

(1998) and Cederberg and Bergström (1999) who suggest possible ways of

improving milk production.

From the dairy’s perspective, an important improvement would be to decrease

the amount of milk required to produce cheese, and in that way reduce the

30

environmental impact from the agriculture, as less milk would need to be

produced. Identifying and minimising the losses of milk during the production

of cheese would lower the consumption of milk without affecting the final

product. There are methods to increase the yield of cheese during the

cheesemaking process, but they all have the drawback of affecting the quality of

the cheese. These methods include increasing the water and salt content of the

cheese, and retaining more whey protein in the curd (Bertelsen et al., 1983,

Johansson, 2001).

Raising the protein content of the incoming milk also gives a better yield of

cheese (Johansson, 2001). The protein content of milk depends on such factors

as the breed of cattle and the fodder used. However, the choice of fodder will

affect the environmental impact of farming; hence, with the information

available, it was not possible to predict how changing this might affect the

outcome of the entire system. Consumers, too, could contribute by minimising

wastage of cheese in the household and reducing car transportation from the

retailer to the household.

4.3 Minimising Environmental Impact by Sequencing Cultured Dairy

Products: Two Case Studies

The diversity of cultured milk products available continues to rise. In Europe

the dairy sector holds the top position in terms of innovative markets in the food

sector (Innovaction, 2003). From the dairy perspective, it is mostly the

production of cultured products that is affected by increased diversity. The

reasons are that it is the cultured products which are available in greatest variety

and also that cultured milk cannot be recycled into the process again. The waste

from cultured milk is either used as animal fodder or, when the water content is

high in the milk residues, it goes to the sewage treatment plant. Loss of product

(also called waste) occurs during each change of product; most of these take

place just before the product is packaged. When product diversity rises, the

31

number of product changes increases and, consequently, a rise in waste of

product occurs. The amount of waste, as well as use of cleaning agents, water

and energy requirements, depends on the products involved in the change.

Therefore the production schedule, where the processing order is decided, is a

key activity for reduction of the rising environmental burden caused by

diversity.

A model was designed to generate the best sequence of products, from an

environmental point of view, which causes the least waste possible while a

constant total volume is produced (Paper III). Two case studies using the

sequencing model were reported in Paper IV. It was found that the dairies do

have options to counteract the environmental effects associated with their

production sequences, for example to use a waste minimised order in the

production planning for each single day of production. A second option was the

frequency of production of each product. By examination of production

schedules on a weekly basis, it was found that the same type of product was

produced as many as five times in the same week. Therefore, scenarios with

variations in the frequency of these types were assessed, using the model (Paper

III), and analysed with LCA methodology.

The frequency with which products are processed was found to have a

significant influence on the amount of waste generated. The results clearly

showed that a decrease in frequency of production per product reduced the

waste generated by the sequence. When the frequency was changed from 2 - 5

times per product and week to twice weekly (from Reference scenario to Goal

scenario, see Section 3.2.1), the waste was decreased from 11 715 kg to 8 698 kg

for Dairy A and from 12 194 kg to 9 301 kg for Dairy B per week. (The dairies

investigated were designated Dairy A and Dairy B.) On a yearly basis, the

reduction of waste would be the amount corresponding to approximately 3.5

days of production for Dairy A and 4 days for Dairy B. It was found to be

32

possible to reduce the product frequency even further, and this was done in the

Future scenario (see Section 3.2.1); this one had a product frequency of 1 - 2

times per product depending on its shelf life. A comparison of the waste

generated each week in the Reference scenario with that in the Future scenario

showed the waste was decreased from 11 715 kg to 5 900 kg for Dairy A and

from 12 194 kg to 7 100 kg for Dairy B per week. On a yearly basis, the

reduction of waste would be the amount corresponding to approximately 7 days

of production at Dairy A and 7.5 days at Dairy B.

Less waste not only reduces environmental impact but also makes economic

savings possible. Dairies can reduce cost not only by decreasing waste but also

by reducing working time. With a changed product frequency, it was possible to

decrease the number of production days by one day per week with the Future A

scenario at Dairy A. At Dairy B the packaging was reduced by one day per

week for one of the machines with the Goal B scenario; packaging was reduced

by another day per week at each of two machines with the Future B scenario.

By changing the product frequency, leading to fewer product changes,

substantial environmental improvement was achieved with reduced product

waste, energy savings, and a decrease in use of cleaning agents and water. In a

life cycle perspective, a decrease of the impact categories of 1.3% was achieved

with the Goal A sequence, and 2.5% with the Future A sequence at Dairy A;

this was 1.5% with Goal B and 2.6% with Future B at Dairy B. By changing the

perspective to the dairy where the actual improvement could take place, it was

revealed that the reduction in environmental impact, for the Goal and Future

scenarios in comparison with the Reference scenario, would be even greater

than the dairies’ own contribution for some categories (Table 2). This result is

due to the extreme dominance of agriculture in the life cycle environmental

impact of dairy products, see Section 2.1 and Paper II.

33

Table 1. The life cycle impact reduction (including agriculture) for the scenarios

Goal and Future (due to fewer product changes than in the Reference scenario),

in relation to each dairy’s environmental impact for the Reference scenario.

GW

(% decrease)

EP

(% decrease)

AC

(% decrease)

POCP

(% decrease)

Dairy A Goal A 33 310 99 22

Future A 63 600 190 43

Dairy B Goal B 38 280 110 25

Future B 68 490 200 45

GW: Global Warming (100 year perspective)

EP: Eutrophication

AC: Acidification

POCP: Photochemical ozone creation potentials.

While a decrease of the product waste generated by any sequence would

probably be an environmental improvement, this depends on the dairy’s

response to alternatives and the consumers´ response to the dairy’s choice. The

dairy has the option to reduce the milk volume processed while maintaining the

same volume of products for sale as before. This offers the environmental

improvements described above. The other option is that the dairy could choose

to raise the volume of products for sale instead. For such a strategy to be

successful the consumers must increase their intake of cultured milk products,

which would mean lowering their intake of other food items. Comparing the

environmental impact of the other food items with that of the cultured milk

products would show whether the environment would become better or worse.

Although production scheduling is not a major issue in environmental work in

dairies today, the clear improvement potential this study shows may change this.

That the product frequency in the production schedule has an impact on waste is

common knowledge within the dairy industry, but that it was shown to be a

parameter of such large magnitude is something new. No study known has been

conducted with processing data to test the role of product frequency before.

34

Another advantage of working with production scheduling is that these

environmental improvements do not involve any equipment investments.

4.4 An Actor Analysis of the Environmental Improvement Potentials in

the Post-Farm Milk Chain Using Life Cycle Assessment

The challenge in working with environmental improvements is to select the

action offering the most substantial progress. However, not all actions are open

to all actors in a product chain. The aim of Paper V was to identify which one of

the measures, i.e. waste reduction, increased transport efficiency, energy savings

or the choice of organic labelled products, offers the greatest improvement

potential for the dairy, the retailer or the household. The products assessed

were milk, cheese, and yoghurt. The systems under study for the three products

were: agriculture, dairy processing, retailer, households and all connected

transports. By collecting data on possible improvements from the post-farm

actors themselves and from literature, and by using these data to recalculate

published LCAs on the selected dairy products, the aim was met.

The result is presented for the three actors individually. For the dairy, no action

stands out as superior to others. It can improve its energy use and transport

system, while also decreasing the wastage. The choice of purchasing organic

products was not considered to be within the power of the dairy. Of the three

product types, the greatest improvement potential is for yoghurt (2% reduction

of the life cycle impact), where all three actions lead to less global warming and

energy use, and decreased wastage also diminishes the eutrophication and

photochemical ozone creation potentials (POCP). For drinking milk dairies,

improving transportation is the most efficient action (reduction of 2%). For

cheesemaking dairies, actions that reduce wastage improve all impact categories

(by 1%), while greater energy efficiency is visible only as decreased use of

energy (by 1%), not as reductions of the other impact categories.

35

The improvement potentials in the retail sector have a limited effect on the life

cycle environmental impact of dairy products. The retailer can reduce its own

wastage and energy use. By adopting more energy efficient refrigerators, the

total life cycle energy use can be decreased by 1%. It is the actions of

households that offer the largest improvement potential. Waste minimisation by

the consumer would clearly lead to significant environmental improvement,

since all impact categories are reduced in this instance (in the range of 2% to

9%). Choosing organic products has a major positive effect on all three products

with regard to energy use (improvement potential in the range of 8 to 14%) and

global warming (2%). However, there is a risk of increasing some impact

categories. Choosing organic milk raises the eutrophication greatly, more than

20%. Also POCP shows a slight rise for cheese (1%). The reason for the high

contribution to eutrophication for organic milk products, a result also reported

by Cederberg and Mattsson (2000), is the high nitrate loss per kilo of milk

produced at an organic farm. This high nitrate loss has two explanations. First,

even though the nitrate loss per hectare is lower in organic farming than in

conventional farming, the yields are also lower, which means a higher nitrate

loss per kilogram yield. Second, the two farming practices differ in the choice of

concentrate feed. Peas, which have a rather high nitrate leakage in relation to

yield, are commonly used in the organic feed. The conventional farm purchases

concentrate feed with a lower nitrate discharge per kg feed (Cederberg and

Mattsson, 2000).

When the possible improvement potentials by the three actors are compared,

the household has by far the greatest improvement potential, followed by the

dairy and then the retail sector. This is because households are less efficient

today, causing large losses; they are still using inefficient home transport and

cold storage. The dairy industry can still make improvements but, since both the

processing and transport are efficient today, the potential for further efficiency

36

is lower in percentage. For example, the waste from the dairy processing of

drinking milk is often reused in the process for yoghurt production.

It should be kept in mind that even if each improvement might seem small in

relative numbers, the dominant part of the environmental impact originates

from a part of the system not directly affected by the actors studied, namely

agriculture. Despite this, some of the improvement actions studied, potentially

undertaken by actors other than agricultural ones, lead to a substantial decrease

in the life cycle environmental impact, for example a decrease of 14% was

achieved in the category energy use by choosing organic cheese.

4.5 Discussion

By comparing the milk supply chain scenarios in Paper I with the ongoing trends

in the food market and the dairy industry (Section 1.1), it is possible to gain an

understanding of the direction of the environmental impacts affected. The

scenario that correlates the most closely with the trend description in Section 1.1

is Splendid Times, based on a positive economic development of society.

Furthermore, the effect of globalisation is shown by production in a few large

specialised dairies. Other similarities are that cultured products and cheese in

small packages are preferred to drinking milk. In spite of the trend, the diversity

of products was not identified as an issue in itself in Paper I. Unfortunately, the

current scenario contributed the most to the environmental impact of the five

assessed; if product diversity had been included, it would have raised the impact

even higher (Paper IV).

To extend the assessment of the trends, the scale of milk processing, changed

consumption pattern, and diversity of products are more thoroughly discussed.

By using the scenarios in Paper I, it was possible to evaluate the differences in

environmental impact in relation to the scale of dairy production. Although the

number of dairies differed in the scenarios, the amount of milk processed was

37

the same. The extreme scenarios with a comparable product portfolio were

Harsh Times, with the fewest dairies, and Green IT-wave, with more than four

times as many. The environmental impact from processing at the dairy, the

transportation from farms to the dairies, and the deliveries from the dairies to

the retailers are likely to be affected by the scale of dairy processing. The

impacts from these activities are summed in Table 3, for both of the scenarios.

Table 3. The differences in environmental impact and energy use caused by the

scale of milk processing. Scenario Harsh Times produced in a few large dairies

and Green IT-wave in several smaller dairies.

NET

(GJ/year)

GW (tonnes

CO2 eq./year)

EP (tonnes O2

eq./year)

AC (kmol H+

eq./year)

POCP

(tonnes ethene

eq./year)

Harsh

Times 2.2 0.95 5600 14 25

Green IT -

Wave 2.5 0.95 4500 12 20

Net: Net energy turnover, i.e. the amount of energy purchased

GW: Global Warming (100 year perspective)

EP: Eutrophication

AC: Acidification

POCP: Photochemical ozone creation potentials

eq: equivalents

When compared with small scale production, large scale dairy production was

not environmentally better to the extent that it could offset the increased impact

of the longer transport distance, see Table 3. This result may be influenced by a

slight difference in the product portfolios, and certainly by the fact that rising

product diversity was not reflected in these scenarios.

The growing diversity of products has consequences during processing, such as a

corresponding rise in product changes, which in turn raises the waste of product,

hence the environmental impact, Paper IV. The environmentally preferred

38

production has as few product changes as possible and when a change is

required the techniques using least resources should be used. During the work

with Papers III and IV, a difference between small dairy companies and large

ones of the effects of product diversity appeared. Small companies with high

product diversity produce only a small volume of each. This implies a large

amount of waste during production of a small volume. It showed that the

amount of waste depending on the product change was sometimes larger than

the amount of product obtained. However, in larger dairy units, where the

produced volume is higher, the proportion between waste and product was

more favourable. It was also found that for the large dairy units studied, the

product order was good and could not be improved in the sense of waste

minimisation. Moreover, we found both in large and small dairy units a great

potential for improvement by reducing the number of times each product was

produced, Paper IV. A high frequency of production of the same type of

product during the same week and also sometimes twice during the same day

was common. The latter was due to late orders from the sales department. This

lack of communication between production and sales management has

environmental and economic consequences. The highlighting of the importance

of production scheduling and the product frequency for the environmental

impact, with consequent economic saving potential, has received a very positive

response from the dairy industry.

An increased consumption of cheese and cultured products at the expense of

drinking milk may change the environmental impact of the dairy chain. In a

qualitative comparison of cheese and milk it was found that cheese is processed

more at the dairy and it is also stored for quite some time to mature, Paper II.

On the other hand, the proportion that should be compared is ten litres of milk

to one kg of cheese, as that is the amount of milk required to produce the

cheese. This has consequences for the packages, as also ten packages are

required for the milk and just one for the cheese, although the type of packaging

39

differs. All transportation after the dairy is also tenfold in volume for the milk.

Furthermore, the loss of drinking milk is higher in the household than the

cheese losses (Paper V). From the comparison of cheese and milk, no

straightforward answer can be given about a change in environmental impact.

However, a qualitative comparison of yoghurt and milk may be done. Yoghurt

is processed more at the dairy and the product diversity is higher, Paper IV.

Large product losses in the household are also a drawback for yoghurt, Paper V.

This comparison indicates that a change in consumption from milk to yoghurt

has negative consequences on the environment. Nevertheless, a comparative

LCA for cheese and milk and for yoghurt and milk are required to obtain

definite answers.

To conclude, the trends in society and industry have negative consequences for

the environmental impact of the dairy chain. First the scenario of Splendid

Times showed that the environmental impact is increasing with the ongoing

trends of today. Then the further assessment of some of the trends generated a

similar result. Large dairy units with long incoming and outgoing transports

have a higher impact than small dairy units. On the other hand, the great

increase in environmental impact caused by the rising variety of cultured

products was found to affect small dairy units the most. A negative

environmental impact would probably occur, if yoghurt were consumed instead

of milk. However, as an exception to a rule, the change in consumption from

milk to cheese is not likely to change the environmental impact.

Everything can be improved, including unwanted environmental effects.

Although within the dairy chain, agriculture is the actor which causes the largest

part of the environmental impact of dairy products, Paper V revealed that the

post-farm actors do have significant options to improve the environmental

impact. For some environmental categories, the improvement potential for an

individual actor was even greater than its own contribution to the category. For

40

example, when the dairy’s reduction of wastage in producing yoghurt was

assessed, a decrease of eutrophication by 2.4 times more than the dairy’s own

contribution was possible.

Another result revealed by this work is the identification of waste of product as

a major environmental issue in a life cycle perspective. For the actors in the

post-farm dairy chain, the waste of milk and product has not previously been

considered an environmental issue except from the perspective of waste

management. However, when the impacts of the common environmental

activities such as transport efficiency, energy savings and organic production

were compared with minimisation of product waste, the latter was as effective as

the other actions; for several environmental categories, it was shown to be the

preferred action (Paper V). Since the waste of product is a parameter that

affects not only the part of the life cycle where it arises, but also the earlier parts

of the chain, it is of significant importance to include the life cycle from the

cradle in an assessment. For milk products this implies that the system boundary

should include the agriculture and further steps in the life cycle before the

product waste occurs. This work deals with milk products, but product waste

minimisation is likely to be a major important environmental issue for all

products with a high environmental impact in the early part of the life cycle, e.g.

meat, aluminium packaging and paper products.

41

5 Methodological Contributions to Environmental Systems

Analysis

A problem solving approach was applied in this work. First, the problem was

identified, then available methodologies were explored. When a suitable

method was lacking, it was necessary to devise one. Two of the Papers, III and

V, contribute to methodology which is described below and followed by a

discussion.

5.1 A Life Cycle Based Method to Minimise Environmental Impact of

Dairy Production through Product Sequencing

The rising number of dairy products affects their environmental impact in a life

cycle perspective. During dairy processing, the production schedule is affected

by more frequent product changes, hence also cleaning operations. This causes

more milk waste, use of cleaning agents, water and energy, which all contribute

to the environmental impact in a life cycle context. To counteract this increasing

environmental impact, a method was developed to schedule a large number of

products in a way that would cause the least possible environmental impact.

During the search for a suitable method, only two studies were found that took

the environment into account during production scheduling: a theoretical study

of process-sequence dependent changeover waste, conducted by Grau et al.

(1995), and a methodology for incorporating ecological considerations into the

optimisation scheduling of a cheesemaking dairy (Stefanis et al., 1997). The

latter included a case-study of a cheesemaking dairy, but included only two

products. Consequently, to solve the problem of sequencing a great number of

products, a new method was required.

The goal of Paper III was to find a practical method to calculate a sequence of a

great number of cultured products, which is optimal or close to optimal, from a

42

waste minimisation perspective. Furthermore, to show the full environmental

implications of the waste minimisation, the sequencing model should be possible

to connect to life cycle assessment (LCA) methodology.

An inter-disciplinary approach was chosen for the method, making use of both

production scheduling and environmental systems analysis. To find the

sequence of products that is optimal from an environmental perspective, the

target function (also called optimisation criterion) must be carefully selected.

Studies of life cycle assessment literature gave us the function. Life cycle

assessments were made for several dairy products, see Section 2.1, and a

consistent finding was that agriculture had the greatest environmental impact.

Consequently, it was concluded, for the remaining parts of the life cycle of dairy

products (the dairy, retailer, consumer household, waste treatment and also all

connected transports), that the action which would offer the best outcome from

an environmental perspective was the minimisation of milk waste. For the

sequencing problem, minimisation of milk waste would also lead to a minimised

use of cleaning agents and water for cleaning during a product change in the

sequence, depending on the techniques used for product changes. Therefore, the

choice of target function fell on milk waste.

The preferred method would be to find an optimised solution through

mathematical optimisation. Nevertheless, this problem has similarities to the

“travelling-salesman-problem” (see Section 3.3.2), which means that to find the

optimal solution involves searching through a vast number of potential

solutions. In practice, this is possible for only a limited number of products

(Sedgewick, 1988). Hence, a heuristic method was developed, which was able to

handle a large number of products, see Section 3.3.1. A drawback to a heuristic

solution is that it cannot be guaranteed that it is also optimal (Hillier and

Lieberman, 1995). Therefore, it was decided to validate the result of the

heuristic method with a sequence achieved through optimisation, with as large a

number of products as could be handled with the optimisation method within a

43

reasonable time. By using techniques to limit the full searches during

optimisation (see Section 3.3.2), 21 products could be scheduled within a

reasonable time (30 minutes). The algorithm was still guaranteed to find the

weight minimised sequence (Sedgewick, 1988).

A sequence was simulated with both the heuristic and the optimised solutions

and then the results were compared. Several starting orders were tested, and the

results from both of the methods always gave the same sequence. Accordingly,

we can state that the heuristic method gives the optimal sequence from an

environmental perspective (that is a waste minimised solution) up to 21

products. This implies that the method used will also find optimal solutions for

all production sequences including fewer products, since all possible

combinations are tested in the algorithm. There is a strong reason to believe,

although it is difficult to prove mathematically, that the heuristic solution for a

sequence including more than 21 products will also be the optimal one, as there

is no known impediment in the sequence that relates to the number of products.

This production scheduling method gives the sequence, for a given set of

products, which causes a presumably minimum amount of milk waste and,

consequently, a low use of cleaning agents and water. Paper III also successfully

demonstrated that the full environmental consequences of production according

to the sequence could be assessed with LCA methodology.

5.2 An Actor Analysis of the Environmental Improvement Potentials in

the Post-Farm Milk Chain using Life Cycle Assessment

To reduce unwanted environmental consequences, a range of actions is

available. The problem is to know what measures offer the most substantial

improvement for each actor. A quantified assessment of the improvement

potential of the actors in the post-farm chain was not found in the literature.

Therefore, a method needed to be devised. The method of life cycle assessment

44

was chosen for the analysis, which was combined with the identification and

quantification of environmental improvement potentials available to the actors

along the post-farm milk chain.

First, ordinary LCAs were undertaken for the products under study (milk,

yoghurt and cheese) to find a reference for the environmental impact of each

product. Then, to select the kind of improvement action to examine, a literature

study was undertaken together with interviews of representatives from the dairy

industry. The most significant measures were found to be increased energy

efficiency, improved transport patterns, reduced product losses and purchase of

organic products. It was decided that neither product nor package changes were

to be considered. Literature study and interviews were used again, this time for

estimation of the improvement potential by each actor along the chain. Then,

the estimated values of the dairies were verified by their representatives.

Thereafter, the LCAs were recalculated using the improvement values for each

measure. To find the greatest potential, the environmental impact of the

modified LCAs and the original ones were compared for each product. To

identify the most efficient action for the dairy, the retailer and the household,

separately, the potential actions of each of them were analysed one at a time.

The method used in this study rests on the availability of reliable LCA data

from the production system, combined with accurate estimates of the

improvement potentials. Also necessary is the life cycle perspective to describe

the full effect of a potential improvement. This is particularly important for

measures dealing with waste reduction.

5.3 Discussion

The combination of environmental systems analysis with production scheduling,

as was used in Paper III, is a new approach to execute product sequencing for

the dairy industry. To choose an environmental systems analysis approach (i.e.

45

LCA) when searching for the environmental target function, used for the

sequencing, was found to be the best way of finding the parameter to minimise

for the most environmental improvement. For sequence solving, operational

analysis was used (a systems analysis methodology), which was then combined

with LCA for evaluation of the environmental impact of the nearly waste

minimised sequence. This approach of finding the production schedule that

contributes the least to the environmental impact, while still producing the same

amount of products, was appropriate for analysis of production with existing

process equipment.

Life cycle assessment studies are often interpreted with dominance and

contribution analyses, i.e. what life cycle phases and particular environmental

loads (emissions and resource consumptions) contribute the most to the over-all

results. In LCA there are seldom interpretations of the sphere of influence of

the various actors along the product chain. Paper V demonstrated the feasibility

of such an approach, by showing that the life cycle environmental implications

of improvement potentials may be quantified on an actor basis. Moreover, a life

cycle approach turned out to be crucial, since measures taken by an actor had

consequences in other parts of the product life cycle.

Both of the methods developed can be used on other product life cycles. The

production scheduling model can be used as it is for any dairy, producing

cultured products. Furthermore, the model can be applied to any batch

production sequence, although the processing rules must be changed to suit the

products under study. The actor analysis methodology suggested can be used as

it is for any life cycle.

46

6 Conclusions

Research for this thesis was guided by a two-fold aim: to increase the knowledge

of the environmental impact of the post-farm dairy chain, while assessing

potential improvement, and to contribute to development of methodology for

environmental systems analysis. This double aim was met in the five appended

papers together. The most important findings are listed.

• The future scenario closest to current trends, as well as the assessments of

production in large units, increased consumption of yoghurt, and the

rising number of cultured products, all highlight an increase in the

environmental impact of the dairy chain.

• The agriculture part is the most dominant contributor to the

environmental impact in the LCA of cheese; the most important

improvement in a life cycle perspective for the cheesemaking dairy is to

decrease its waste of milk and cheese.

• A method of constructing the environmentally preferred, life cycle based,

production sequence was developed for cultured dairy products. Using

the method will result in both environmental and economic savings for

the dairy.

• Reduction of the frequency of production of each cultured product lowers

the environmental impact.

• An actor analysis method was devised to help the actors to find the

measure that makes most substantial environmental improvement in a life

cycle perspective.

• Waste of product was revealed to be a key issue for environmental

consequences in a life cycle perspective, and reducing the waste offers a

substantial decrease in the impact.

47

7 Future Work

The research done in this thesis has provoked other interesting questions. As

waste of product turned out to be such an important environmental issue for the

dairy chain, although it had not previously been seen as one, I have several

suggestions about product waste. First, since the consumer has a large influence

on the environmental impact, which involves great losses of product, and data

about household losses is very poor, a thorough assessment of consumer

behaviour is needed. Second, more accurate information about losses of milk

and products at the other parts of the post-farm chain, such as the retailer and

dairy, is also needed. Third, an assessment of milk waste sources from the

milking in the phase of agriculture would be useful. Fourth, the scope can be

broadened to the whole food chain, and to cover the losses for Sweden. Almost

certainly, the environmental impact from the losses makes up a large part of the

total impact of the food sector.

This thesis has revealed that increasing the diversity of cultured dairy products

raises the environmental impact, both in a life cycle perspective and at the dairy

unit. This trend can be assumed to continue, by observing the dairy shelves at

German or British retailers, since Sweden still has fewer products; this is likely

to be an even more important issue in the future. The consequences would be

greatest for small dairy units, with rising losses of product leading to an increase

in environmental impact as well as economic losses. When considering small

dairy units compared with larger ones, the issue of the increasing diversity in

dairy products should be included. Therefore, a suggestion is to update and

improve the scenarios of Paper I with respect to the consequences of an

increasing number of dairy products.

A specific suggestion for improvement of the dairy process is to reduce the milk

waste in dairies by production scheduling, and to combine it with better

48

monitoring of the losses. Henningsson (2005) showed how to reduce losses by

increasing the control of them with an optical instrument, conductivity meter

and density meter. This would decrease the amount of waste during each

product change independently of changing techniques used. Combining the

waste minimised sequence with Henningsson’s monitoring methods would be

very interesting and has great potential indeed.

The final suggestion is to use the actor analysis method for other food chains.

I will conclude this thesis with a recommendation for environmental

improvement: Let us keep in mind that each food item has an environmental

history. If a food product is wasted instead of consumed, all of the

environmental impact that it has caused during its life cycle has happened for

nothing. So think about the environment, and eat up your food!

49

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