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MASTER’S THESISEvaluation of possible SIX SIGMA implementation including a DMAIC project A case study at the Cage Factory, SKF Sverige AB MASTER OF SCIENCE PROGRAMME Department of Busine

MASTER’S THESIS

Evaluation of possible

SIX SIGMA implementation including a DMAIC project

A case study at the Cage Factory, SKF Sverige AB

MASTER OF SCIENCE PROGRAMME

Department of Business Administration and Social Science Division of Quality & Environmental ManagementMARTIN LENNARTSSON ERIK VANHATALO

Evaluation of possible SIX SIGMA implementation

including a DMAIC project

- A CASE STUDY AT THE CAGE FACTORY, SKF SVERIGE AB

Utvärdering av möjlig SEX SIGMA implementering

samt ett DMAIC-projekt

- EN FALLSTUDIE PÅ HÅLLAREFABRIKEN, SKF SVERIGE AB

This Master Thesis was carried out within the area of Quality Management

at Luleå University of Technology and SKF Sverige AB

Lars Palmqvist, SKF Sverige AB in Gothenburg

Karin Schön, Luleå University of Technology

ABSTRACT

Six Sigma is an initiative launched by Motorola in 1987, focusing on reducing variation and continuously improving processes (Barney, 2002) This thesis was carried out at the Cage Factory in Gothenburg, a smaller unit within SKF Sverige AB with 124 employees The factory manufactures the cage component in the bearing, which will keep the rollers in place in the complete bearing

The purpose of this thesis is to investigate and make comparisons between Six Sigma and the existing way of working with improvements and the organization in the Cage Factory and to give recommendations on what actions are needed to efficiently implement Six Sigma

To aid in the fulfillment of the purpose a practical DMAIC (Define- Measure-Analyze-Improve-Control) project was conducted The project aims to reduce customer complaints and downtime caused by the turning activity in one of the production channels at the Cage Factory Furthermore, several interviews with strategically selected individuals were conducted The authors argue that Six Sigma could be implemented and integrated with the existing improvement approach, Total Process Management, TPMG Six Sigma can be used to attack the most complex problems, while TPMG handles the many day-to-day issues

At the moment the implementation strategy "Strategically selected individuals and projects" is the most applicable at the Cage Factory The authors argue that Six Sigma will provide a structure (DMAIC) and training

in tools, thereby ensuring that the tools are used at the right time and in the right way at the Cage Factory

In the future, there has to be a strategy for generating possible Six Sigma projects at the Cage Factory Also, it is important that a way for steering different problems to different problem solving activities is developed

However, some issues need to be considered if Six Sigma should work efficiently at the Cage Factory A training venture is needed to enable the introduction of different roles in the organization Also, all training should

be connected to practical experience It is important that the Cage Factory receives resource support from SKF Sverige and/or the SKF Group Further,

a reliable measurement system must be implemented The authors believe that improved scrap reporting and improved use of SPC are important actions that need to be taken

SAMMANFATTNING

Sex Sigma fokuserar på att reducera variation samt att kontinuerligt förbättra företagets processer och introducerades av Motorola 1987 (Barney, 2002) Detta examensarbete har utförts på Hållarefabriken i Göteborg som är en mindre enhet inom SKF Sverige AB med 124 anställda Fabriken producerar hållarkomponenten i lagret som har till uppgift att hålla rullar på plats i det färdiga lagret

Syftet med examensarbetet är att utvärdera och jämföra Sex Sigma med det rådande förbättringsarbetet och organisationen på Hållarefabriken samt att

ge rekommendationer på vad som bör åtgärdas för att effektivt kunna införa Sex Sigma

För att uppfylla syftet har bland annat ett DMAIC-projekt utförts Projektets syfte är att reducera antalet kundreklamationer och minska stopptid orsakade

av svarvning i en av produktionskanalerna på Hållarefabriken Vidare har ett antal intervjuer genomförts med strategiskt utvalda individer

Författarna menar att Sex Sigma kan implementeras och integreras i det nuvarande förbättringsarbetet, Total Process Management (TPMG) Sex Sigma kan användas för att attackera de mest komplexa problemen inom verksamheten, medan TPMG hanterar de vardagliga åtgärderna som krävs för att utveckla verksamheten på lång sikt

För tillfället är implementeringsstrategin "strategiskt utvalda individer och projekt" den mest lämpliga för Hållarefabriken Författarna anser att Sex Sigma kommer att ge en struktur (DMAIC) och träning i verktyg, vilket i sin tur innebär att verktygen används vid rätt tillfälle och på rätt sätt på Hållarefabriken

I framtiden måste det finnas en strategi för att generera möjliga Sex projekt på Hållarefabriken Dessutom är det viktigt att det utvecklas ett sätt att styra olika problem till olika problemlösningsalternativ

Sigma-Det finns dock en del åtgärder som måste vidtas för att Sex Sigma ska kunna fungera effektivt på Hållarefabriken En utbildningssatsning krävs för att möjliggöra en introduktion av roller i organisationen All utbildning bör dessutom ske i samband med deltagandet i ett praktiskt projekt Det är viktigt att Hållarefabriken får stöd, i form av resurser, från SKF Sverige och SKF-koncernen Författarna anser att en förbättrad kassationsrapportering och förbättrad användning av programvaran för SPS är viktiga åtgärder för

ACKNOWLEDGEMENTS

This Master Thesis was carried out during the period from late September

2003 to early February 2004 at the Cage Factory, SKF Sverige AB in Gothenburg, Sweden

We would like to take the opportunity to thank SKF Sverige AB and especially the Cage Factory's entire staff for giving us the opportunity to write our Master Thesis by studying their organization

Furthermore, we also wish to thank our supervisor at Luleå University of Technology, Luleå, LTU, Karin Schön as well as our supervisor at the Cage Factory Lars Palmqvist for their valuable support during the completion of this Thesis

Moreover, the authors would like to express a special thanks to the members

of the improvement group taking part in the DMAIC project presented in this Thesis Without their committed participation this Thesis' completion wouldn't have been possible Also, we thank all the different individuals that gave us some of their valuable time taking part in the interviews made in this Thesis

Last but not least, we would like to thank the Division of Quality and Environmental Management at LTU for the opportunity to complete our Master's study at their Division and for support during this and earlier courses Especially we would like to thank Görgen Edenhagen, Master Thesis Coordinator and fellow course mates giving us feedback at Master Student's seminars

Gothenburg, February 2004

CONTENTS

LIST OF FIGURES, PICTURES AND TABLES 1

FIGURES 1

PICTURES 2

TABLES 2

LIST OF ABBREVIATIONS 3

1 INTRODUCTION 4

1.1 BACKGROUND 4

1.1.1 The development of quality engineering 4

1.1.2 Company presentation 6

1.2 PROBLEM DISCUSSION 8

1.3 PURPOSE AND DELIMITATIONS 10

1.3.1 Purpose of the thesis 10

1.3.2 Delimitations 10

1.4 THE OUTLINE OF THE THESIS 11

2 METHODOLOGY 12

2.1 RESEARCH APPROACH 12

2.1.1 Positivism or Hermeneutics 12

2.1.2 Induction or Deduction 13

2.1.3 Quantitative or Qualitative method 14

2.2 RESEARCH STRATEGY 14

2.3 LITERATURE STUDY 15

2.4 CHOICE OF DATA COLLECTION METHOD 16

2.4.1 Primary data 16

2.4.2 Secondary data 18

2.5 METHODOLOGY AND CHOSEN TOOLS IN THE DMAIC PROJECT 18

2.6 RELIABILITY AND VALIDITY 19

2.6.1 Validity 19

2.6.2 Reliability 20

3 THEORETICAL FRAME OF REFERENCE 21

3.1 SIX SIGMA 21

3.1.1 The Six Sigma Framework 23

3.1.2 The Six Sigma Infrastructure 24

3.1.3 Strategies for Six Sigma Implementation 25

3.1.4 Critique to Six Sigma 27

3.2.1 How to choose a Six Sigma project 29

3.2.2 The Define Phase 29

3.2.3 The Measure Phase 30

3.2.4 The Analyze Phase 31

3.2.5 The Improve Phase 31

3.2.6 The Control Phase 31

3.2.7 Examples of tools in the different phases 32

3.2.8 Tools Chosen in the DMAIC project 33

3.3 OTHER QUALITY INITIATIVES 34

3.3.1 Total Quality Management, TQM 34

3.3.2 Total Process Management and TPM, the SKF way 35

3.4 TURNING 37

4 THE EMPIRICAL STUDY 38

4.1 THE DMAIC PROJECT 38

4.1.1 The Define Phase 38

4.1.2 The Measure Phase 41

4.1.3 The Analyze Phase 47

4.1.4 The Improve Phase 49

4.1.5 The Control Phase 52

4.1.6 Evaluation of the DMAIC project 53

4.2 INTERVIEWS 54

4.2.1 Lars Arrenäs, TPMG Manager, SKF 55

4.2.2 Cecilia Lack, TPMG Coordinator at the Cage Factory 56

4.2.3 Folke Höglund, Quality Assurance Manager, SKF Group 57

4.2.4 Bo Bergman, Professor, Chalmers University of Technology, CTH 59

4.2.5 Laszlo Persson, Master Black Belt at Volvo Cars Engine in Skövde 61

4.3 FOCUS GROUP AT THE CAGE FACTORY 68

5 ANALYSIS AND RESULTS 72

5.1 EXPERIENCE FROM THE DMAIC PROJECT 72

5.1.1 The scope of the project 72

5.1.2 The cost issue 73

5.1.3 Collection and evaluation of data 73

5.1.4 DMAIC methodology, tools and results 74

5.2 ANALYSIS OF SIX SIGMA IMPLEMENTATION AT THE CAGE FACTORY 76

5.2.1 Why adopt Six Sigma? 76

5.2.2 The Six Sigma Framework at the Cage Factory 77

5.2.3 Organization and Six Sigma Roles 80

5.2.4 Methodology and Tools 81

6 CONCLUSIONS AND DISCUSSION 82

6.1 CONCLUSIONS 82

6.2 DISCUSSION 83

6.2.1 Thesis generalization 83

6.2.2 Criticism to sources and methodology 83

6.2.3 Problems with the purpose of the thesis 85

6.2.4 Future work 85

REFERENCES 86

BIBLIOGRAPHIC REFERENCES 86

ELECTRONIC REFERENCES 87

PAPER REFERENCES 88

ORAL REFERENCES 88

OTHER REFERENCES 89

SUPPLEMENTS 90

APPENDICES 102

GLOSSARY 110

INDEX 111

LIST OF FIGURES, PICTURES AND TABLES

Figures

Page

FIGURE 1.1 DEVELOPMENT OF THE QUALITY CONCEPT 5

FIGURE 1.2 THE SKF BUSINESS CONCEPT 6

FIGURE 1.3 THE SKF QUALITY POLICY 7

FIGURE 1.4 SKETCH OF THE WORKFLOW IN CHANNEL 13 AT THE CAGE FACTORY 9

FIGURE 2.1 INDUCTIVE AND DEDUCTIVE APPROACH IN RESEARCH 13

FIGURE 3.1 NORMALLY DISTRIBUTED PROCESS PERFORMING AT SIX SIGMA LEVEL 22

FIGURE 3.2 COSTS, IN PER CENT OF TURNOVER, DEPENDING ON SIGMA LEVEL 22

FIGURE 3.3 THE CORPORATE FRAMEWORK OF SIX SIGMA 23

FIGURE 3.4 STRUCTURE OF A GENERAL SIX SIGMA PROJECT 25

FIGURE 3.5 STRATEGIES FOR SIX SIGMA IMPLEMENTATION 26

FIGURE 3.6 THE DMAIC METHODOLOGY 28

FIGURE 3.7 COMMONLY USED SOURCES FOR PROJECT GENERATION 29

FIGURE 3.8 VARIATION IN INPUT VARIABLES ARE TRANSFERRED TO THE OUTPUT 30

FIGURE 3.9 COMMONLY USED TOOLS IN A DMAIC PROJECT 33

FIGURE 3.10 QUALITY TOOLS IN THE DMAIC PROJECT 33

FIGURE 3.11 LINK BETWEEN VALUES, METHODOLOGIES AND TOOLS 35

FIGURE 3.12 THE OPERATOR MAINTENANCE STAIRCASE 36

FIGURE 3.13 THE CONCEPT OF LONGITUDINAL AND FACE TURNING 37

FIGURE 4.1 PARETO CHART OVER CUSTOMER COMPLAINTS 39

FIGURE 4.2 HISTORICAL DEVELOPMENT OF COMPLAINTS IN CHANNEL 13 39

FIGURE 4.3 PARETO CHART FOR IDENTIFIED COMPLAINT CAUSES IN CHANNEL 13 39

FIGURE 4.4 PROCESS MAP OF THE TURNING ACTIVITY 41

FIGURE 4.5 PIE CHART OF DOWNTIME IN DIFFERENT MACHINES IN CHANNEL 13 42

FIGURE 4.6 PARETO CHART OF DURATIONS FOR DIFFERENT CAUSES 43

FIGURE 4.7 RESULT OF THE FREQUENCY STUDY IN THE TURNING PROCESS 44

FIGURE 4.8 THE OUT OF CONTROL SITUATION FOR ONE OF THE STUDIED CAGES 49

FIGURE 4.9 THE KANO MODEL 60

FIGURE 4.10SKETCH OF THE SIX SIGMA ORGANIZATIONAL STRUCTURE AT VCES 64

FIGURE 4.11PROJECT LIFE AND RESPONSIBILITIES AT VCES 65

FIGURE 4.12 PROBLEM SOLVING ACTIVITIES AT VCES 65

FIGURE 5.1 HOW SIX SIGMA AND TPMG DEALS WITH PROBLEMS 77

FIGURE 5.2 TPMG AND SIX SIGMA AT THE CAGE FACTORY 79

FIGURE S.1 PROJECT CHARTER USED IN THE DMAIC PROJECT 92

FIGURE S.2 FREQUENCY STUDY FORM USED IN THE DMAIC PROJECT 93

FIGURE S.3 CAUSE-AND-EFFECT DIAGRAM FROM THE DMAIC PROJECT 95

FIGURE S.4 PROCESS-FMEA DEVELOPED IN THE DMAIC PROJECT 98

FIGURE S.5TREE DIAGRAM DEVELOPED IN THE DMAIC PROJECT 100

FIGURE S.6 MATRIX DIAGRAM DEVELOPED IN THE DMAIC PROJECT 101

FIGURE A.1 CONVERTING DPMO TO SIGMA VALUES 103

FIGURE A.2 THE SEVEN-TIMES-SEVEN TOOLBOX 104

Pictures PICTURE 1.1 CAGE AND RADIAL BEARING 7

PICTURE 4.1THE IMPROVEMENT GROUP 42

PICTURE 4.2 DEFECTS IN THE TURNING ACTIVITY 44

Tables TABLE 4.1 CUSTOMER COMPLAINTS PER PRODUCTION CHANNEL 38

TABLE 4.2 POTENTIAL FAILURE CAUSES WITH THE HIGHEST RPN 48

TABLE 4.3 MEASURES FROM THE TREE DIAGRAM WITH 18 POINTS 50

TABLE 4.4 MEASURES CORRELATED TO PROBLEMS DETECTED IN THE FMEA 51

TABLE S.1 THE CUSTOMER COMPLAINT PROCESS 96

TABLE A.1 TRAINING CONTENT FOR DIFFERENT ROLES 103

LIST OF ABBREVIATIONS

ABB Asea Brown Bovery

ANOVA Analysis of Variance

ANOM Analysis of Means

C p Process Capability Ratio

C pk Process Capability Ratio, considering centering

CTH Chalmers University of Technology

CTQ Critical To Quality

DFSS Design For Six Sigma

DMAIC Define, Measure, Analyze, Improve, Control

DPMO Defects Per Million Opportunities

DOE Design Of Experiments

FADE Focus, Analyze, Deploy and Evaluate

FMEA Failure Modes and Effects Analysis

H1, H2, H3 Production Section 1, 2 and 3 in the Cage Factory

ISO International Standardization Organization

KLEMM "Kvalitet" (Quality), "Leverans" (Delivery), "Ekonomi" (Economy), "Miljö"

(Environment) and "Medarbetare" (Co-worker)

KTI Kvalitets Tillstånds Information (Quality State Information)

LSL Lower Specification Limit

LTU Luleå University of Technology

MBNQA Malcolm Baldridge National Quality Award

MCSS Manufacturing Customer Service System

NC Numerically Controlled

PDCA Plan, Do, Check, Act

PTS Project Tracking System

QFD Quality Function Deployment

QIT Quality Improvement Teams

PCR Process Capability Ratio

R&R Repeatability & Rreproducibility

RPN Risk Priority Number

SEK Swedish Krona (Currency)

SIPOC Suppliers, Inputs, Process, Outputs, Control

SIQ Institutet För Kvalitetsutveckling

SKF Svenska Kullagerfabriken

SPC Statistical Process Control

TPM Total Productive Maintenance

TPMG Total Process Management

TQM Total Quality Management

TRIZ Theory of Inventive Problem Solving

USL Upper Specification Limit

VCES Volvo Cars Engine in Skövde

VMEA Variance Mode and Effect Analysis

VOC Voice Of Customer

1 INTRODUCTION

This chapter begins with the background of the thesis, containing an overview of the quality concept and a company presentation Then a problem discussion will follow and finally the purpose and delimitations of the thesis will be presented to the reader

1.1 Background

1.1.1 The development of quality engineering

An important question that Company Managers are asking themselves is "How do

we become successful?", but a question of equal importance is “How do we stay successful in the future?” (Pande, Neuman & Cavangh, 2000)

A company cannot survive without customers According to Pyzdek (2003) it is therefore very important that the company provides products that the customers are willing to pay for In plain language this means that the ultimate goal for the company is to create value to the customer Hence, the customer settles the quality

of a product

The word quality has its origin from the Latin word "qualitas”, which means

“character” (Bergman & Klefsjö, 2001) There are several different definitions of the Quality Concept and many different opinions of what should be included in the concept of product quality The authors have fallen for a definition of the quality of

a product from Bergman & Klefsjö (2001):

"The quality of a product is its ability to satisfy and preferably exceed the needs and expectations of the customers"

(Translated from Bergman & Klefsjö, 2001 p.24)

The approaches that have been used to deal with quality problems have changed over time Bergman & Klefsjö (2001) mean that the dominating quality technique used shortly after World War II was Quality Control of finished products, a defensive technique Since then, the development direction has been to increase the efforts before the production process begins and also to work with continuous improvements This development is illustrated in Figure 1.1 The Swedish Institute

of Quality, SIQ, shares this point of view (SIQ, 2003)

Quality Management…continuous improvements before, during and after production

Quality Control …after production

Figure 1.1 Development of the Quality Concept from the middle of the twentieth century

Source: Bergman & Klefsjö (2001, p.94)

In the more recent history of the quality development, the quality improvement

program Six Sigma has been successful The American company Motorola

developed Six Sigma as a consequence of poor quality and customer complaints, which affected the competitive power of the company negatively (Barney, 2002)

In 1986 Bill Smith, engineer and statistician at Motorola, introduced the Six Sigma concept aiming to attack the existing quality problems in the company

Motorola began documenting their key processes, aligning them toward customer requirements, measuring and analyzing to be able to improve their processes continuously and reduce variation (Barney, 2002)

and the interest for Six Sigma increased (Pyzdek, 2001)

Since Motorola launched Six Sigma in 1987 and particularly from 1995, a growing number of global companies have followed, developing Six Sigma programs of their own (Magnusson, Kroslid & Bergman, 2003) Today, Six Sigma is well established in the automotive, aviation, chemical, electronic and metallurgy industries (ibid)

A recent successful example of Six Sigma implementation in Sweden is Volvo Cars Corp., which after three years and around 500 completed Six Sigma projects presents net savings of about one Billion SEK (Dahlquist, 2003)

Bergman & Klefsjö (2001) claims that the goal of Six Sigma is to substantially reduce unwanted variation that either results in cost reductions or increased customer satisfaction The reduced variation may also lead to improved delivery performance and increased process yield

1

The MBNQA is an annual quality award in the USA and was established in 1987 when the sitting president Ronald Reagan signed the MBNQ improvement Act The award is named after a former American Secretary of Commerse, Malcolm Baldridge (Dale, 1999)

1.1.2 Company presentation

Findings of simple forms of ball bearings from archeological excavations have been dated to the days of the Roman Empire The basic function of a bearing is to facilitate the rotation of wheels and axles When the bicycle with pedals was

easier for the user to ride the bike This sped up the development of ball bearings

ball bearing and later that year he founded "Svenska KullagerFabriken", (the

Swedish Ball Bearing Factory), SKF (SKF, 2003a)

In 2002 The SKF Group, having business activities at 79 locations around the world, had an annual turnover exceeding SEK 42 Billion and presented a pre-tax profit of SEK 3.5 Billion The SKF Group employs 39,700 people, of which 4,600

in Sweden (SKF, 2003e)

The SKF Group has five subdivisions: Automotive, Electrical, Industrial, Service and Aero and Steel Division These divisions also include a number of subsidiaries

located in different countries around the world

In Sweden the activities are centered round SKF Sverige AB and its thirteen subsidiaries, which work with everything from refining raw material to business development (SKF, 2003c)

The SKF business concept is presented in Figure 1.2

SKF's mission is to enhance and develop global leadership in bearings, seals, related products,

systems and services

Our aim is to be the best in the industry at:

- providing customer value

- developing our employees

- creating shareholder value

Figure 1.2 The SKF Business Concept

SKF's attitude and commitment to quality is communicated through the Quality Policy, which is displayed in Figure 1.3

2

A self-aligning bearing is characterized by its ability to adjust to skewed axles This is possible because

Aim for Total Quality in everything we do

Market only products and services that will ensure customer satisfaction by:

- Operating reliable and capable processes

Figure 1.3 The SKF Quality Policy

SKF's largest individual customer is the French Railway Other important customer segments are for example crushing machine manufacturers, paper mills and wind power plants (Huttunen, 2003)

This thesis is focusing on the situation at the Cage Factory, SKF Sverige in Gothenburg The factory is manufacturing the cage component in a bearing The function of a cage is to keep the rollers in place in the complete bearing Picture 1.1 shows a cage for a radial bearing There are 124 employees at the factory and the annual turnover is about SEK 170 Million The factory is divided into three sections with a total of 14 production flows There are about 200 standard versions

of cages in production with dimensions 100-2,008 mm in diameter (Huttunen, 2003)

70 per cent of the production moves on to assembly at SKF's other factories in Gothenburg More then 20 per cent are assembled at factories in the USA and the remaining part goes to factories in England and Malaysia The annual production is

which constitute about 95 per cent of the production (ibid) A cage for a radial

bearing and a complete radial bearing can be viewed in Picture 1.1

1.2 Problem discussion

There are many ways to deal with quality problems in a manufacturing company The past 15-20 years many new methods, strategies and tools have emerged in the quality area, for example Total Quality Management, TQM, has been a popular approach that many companies have adopted (Pande et al., 2000)

In recent years Six Sigma has grown in popularity especially in the US and companies like General Electric and Motorola have obtained significant improvements in their performance (Pande et al., 2000) A reason for their success

is probably Six Sigma's ability to prove reduced costs or higher profits in economical measures

The SKF Group has taken a decision to start a Six Sigma initiative within the entire group during 2004 Each division will be responsible for its own time plan to launch Six Sigma (de Laval, 2003)

Earlier, the Automotive Division has decided to start a Six Sigma initiative within the division and has recently started a Black Belt training program Chicago Rawhide (USA) for example, working in the seal area has completed roughly, 300-

400 Six Sigma projects (Nielsen, 2003)

The Cage Factory is a part of the Industrial Division, which has shown an early interest for investigating how Six Sigma could be implemented in the division Therefore an evaluation of Six Sigma implementation in the Cage Factory is valuable

In a traditional organization the structure is designed to carry out routine tasks In Six Sigma most activities and problems are unique (Pyzdek, 2003) What is this demanding of the Six Sigma Company?

A company that aims for an implementation of Six Sigma also has to consider ongoing improvement activities and systems Management must therefore plan how overlapping activities should be organized in a way to prevent confusion and reach

a positive cooperation between the current system and Six Sigma (Pyzdek, 2003)

There is a five years old Total Process Management initiative running at the Cage

Factory, which has to be taken into consideration Other aspects, such as different culture and employee devotion, also have to be considered

As mentioned previously, there are fourteen different production flows in the Cage Factory The workflow is principally divided into the same main activities

These are shown in Figure 1.4 (main activities in bold font) The figure displays

Washing:

Remove superfluous oil

- Correct dimensions for the cage

- Eliminate non-conformities in surface

Packing:

Packing of complete cages

There has been an increase of complaints in Channel 13 until October 2003 Most

of these complaints can be derived from Turning (activity F in Figure 1.4.) The

cages are turned on two sides as showed in Picture 1.2 The two sides of the Cage

are called small end and large end There are both esthetical and capability

problems There are also efficiency losses, in form of downtime, connected to these

problems

companies, has become increasingly common (Pande et al., 2000)

Small end

of cage

Large end of Cage

Picture 1.2 Turning surface on large end and small end of the Cage Source: Own work

This particular problem provides an opportunity to further investigate if and how

the Six Sigma methodology (DMAIC) and tools can be used successfully in the

Cage Factory

4

The acronym DMAIC is an abbreviation for the five phases in the Six Sigma improvement project,

namely Define, Measure, Analyze, Improve and Control

1.3 Purpose and delimitations

1.3.1 Purpose of the thesis

The main purpose of this thesis is to evaluate and make comparisons between Six Sigma and the existing way of working and the organization in the Cage Factory This will end up in recommendations on how Six Sigma can be implemented in the Cage Factory and which actions need to be taken to efficiently work with Six Sigma in the organization

To aid in the fulfillment of the main purpose a practical improvement project will

be carried out In this project the DMAIC methodology will be used The practical part of the project will deal with quality shortages in the production process concerning the turning device, analyzing the reasons for these shortages and suggesting actions to improve the situation

1.3.2 Delimitations

When studying the possibility of Six Sigma implementation the focus will be on how, and in which form, a Six Sigma venture can exist within the current organization and how a general Six Sigma project can be conducted

The authors have chosen not to study the possibility of implementing Design For Six Sigma, DFSS, at the Cage Factory This choice was made since the authors have a limited time of 20 weeks to conduct the study Also, a natural starting point

of a Six Sigma venture is the use of Six Sigma in the production and not in the design phase (Professor Bergman, 2003)

The practical improvement project will deal with quality shortages in the turning device in Production Channel 13, since there has been an increase of customer complaints in the Channel until October 2003

The authors decided to study only one of the turning devices in one of the production channels because of the complexity of the process and the limited time available The types that are being produced in Channel 13 during the time of the study limit the types of Cages that will be included in the study

The improvement project will be carried out between 2003-10-01 and 2004-01-13 Since the authors have a limited amount of time to conduct the practical improvement project the Control Phase in the DMAIC cycle will not be carried out This phase need several months of monitoring to be properly evaluated The authors will instead give recommendations on how this phase could be conducted.The thesis will not take all possible Six Sigma tools into account but a selection of appropriate tools will be used in the different phases

1.4 The outline of the thesis

In this section the outline of the thesis is presented to the reader An overview of the following chapters is given in Figure 1.5 The figure is also an attempt to present a composition of the thesis to the reader

Figure 1.5 The outline of the thesis

The first chapter gives the reader an introduction to the thesis The second chapter discusses the methodology chosen to solve the problem Since the authors have chosen a deductive approach (see Section 2.1.2), the theoretical frame of reference

is then presented to the reader in chapter three Chapter 4 contains the results of the empirical study at the Cage Factory These results are then analyzed in Chapter 5 and finally, in Chapter 6, the authors' conclusions and a general discussion are presented

2 METHODOLOGY

In this chapter the methodology of the thesis is presented Different aspects of the research approach and research strategy are discussed The chapter also describes the study of literature, choice of data collection, methodology and chosen tools in the DMAIC project and finally a discussion of the validity and reliability of the thesis

Holme & Solvang (1991) argue that methodology is a tool or a way to solve problems and thereby get new knowledge Everything that is helping the researchers to reach their goals is methodology

2.1 Research approach

A governing thought within modern science is that research results should be published and used freely to aid the growth of science Other researchers must be able to review models, methods and results Are the data valid? Are the interpretations and analyses reliable? Are the conclusions only applicable under certain circumstances or are they of a more general nature? (Wiedersheim-Paul & Eriksson, 1993)

The opposite of Positivism is Hermeneutics, which can be translated to interpretation science and origins in theories about bible and other text interpretations Hermeneutics is about interpretation of meanings in its widest sense (Wallén 1993)

This thesis, investigating a possible Six Sigma implementation at the Cage Factory, has got elements of both Hermeneutics and Positivism Qualitative data is collected through interviews, a focus group and by running a DMAIC project The authors' interpretations and analysis of these sources of data, founded upon interpretations

However, there are also elements of Positivism The DMAIC project concerning the turning related problems also includes quantitative data and logical and fact-based decisions, a positivistic approach In fact, the evaluation of a possible Six Sigma implementation must be based on observations and empirical results from the current situation at the Cage Factory, consequently a positivistic approach

2.1.2 Induction or Deduction

Rationalism is a philosophical branch, which claims that it is possible to obtain knowledge about reality only by using reason (Nationalencyklopedin, 2003) Empiricism on the other hand is a branch that, in contrast to rationalism, emphasizes experience as the base of our knowledge (Prawitz, 2003) According to Wiedersheim-Paul & Eriksson (1993) empiricism and rationalism lead to two

principally different approaches to research, see Figure 2.1, Deduction and

This thesis has got a deductive approach The starting-point of the thesis is a review

of existing theories in the area Then the empirical studies are conducted, after which the empirical results are analyzed on the basis of existing theories

2.1.3 Quantitative or Qualitative method

Holme & Solvang (1991) argue that there are principally two different types of research methods, quantitative and qualitative methods

Qualitative data consists of detailed descriptions of for example situations, events and people It can give information about different people's experiences, attitudes, opinions and thoughts Quantitative data give information about how many, how much, amount, frequency and the distribution of the data (Merriam, 1994)

Qualitative methods have primarily a purpose of understanding and by using different data collection methods get a deeper understanding of the studied problem (Holme & Solvang, 1991) Quantitative methods are more formalized and structured and often mean more control from the researcher Statistical methods play an important role within quantitative research (ibid)

According to Holme & Solvang (1991) it can be successful to combine qualitative and quantitative methods because advantages and drawbacks with each method complement each other

In this thesis there are elements of both qualitative and quantitative data or information The majority of the data or information gathered is of a qualitative nature, in the form of interviews, focus groups and the use of qualitative tools in the improvement project However, quantitative data or information is also gathered by the use of check sheets and review of quantitative data provided by SKF from the turning process

2.2 Research strategy

There are several ways of doing research Examples are experiments, surveys, historical studies, analyses of archival information and case studies (Yin, 1994) According to Yin (1994), case studies are the preferred strategy when the questions

"how" or "why" are being asked In this thesis, questions like "how can the Six Sigma methodology be implemented to improve the existing production process?" and "how and why should SKF introduce Six Sigma in the organization?" are valid

To be able to fulfill the purpose of the thesis, the authors concluded that a thorough study of the company's current way of working was needed Likewise the authors saw the need for a careful analysis of the DMAIC project

This motivated the choice of a Case Study as the starting point of the data collection methods used in the thesis

Yin (1994 p 3) describes the Case Study strategy as follows:

"In brief, the Case Study allows an investigation to retain the holistic and meaningful characteristics of real-life events - such as individual life cycles, organizational and managerial processes, neighborhood change, international relations and the maturation of industries."

According to Wallén (1993) the advantages of a Case Study are that the research is carried out under real circumstances and it provides the possibility to generate in-depth knowledge about the research object The Case Study is often very useful in such research The strategy is then used as an alternative approach together with other methods

The purpose of a Case Study is simply to take a small part of a whole course of events to let the case represent and describe reality (Ejvegård, 1996)

Merriam (1994) argue that all types of methods to gather scientific information can

be used in a Case Study, both qualitative and quantitative ones

According to Yin (1994 p.9-10) the weaknesses of the Case Study are:

− It is not uncommon that equivocal information and/or biased views are allowed to influence the conclusions of the Case Study

− Case studies provide a rather little basis for scientific generalization

− Case studies can become massive and take too long time, hence being hard to analyze

These shortages need to be considered by the authors as they can affect both the validity and the reliability of the thesis

2.3 Literature study

As the authors have chosen a deductive approach, which uses theories as a starting point of the research, there was a need for an extensive literature study

Since Six Sigma is an approach with many different advocates, the authors decided

to look for information about Six Sigma from a number of authors to get an own objective point of view Three books about Six Sigma used frequently by the authors are: Magnusson, Kroslid & Bergman (2003), Pande, Neuman & Cavangh (2000) and Pyzdek (2003) The first one displays a Swedish point of view of Six Sigma while the other two are American

These books were chosen because Six Sigma was originally an American

"invention" and the Swedish book will give a Swedish perspective of the Six Sigma concept

Other books in the quality field that will be referred to are literature about TPM, TQM and Statistical Process Control, SPC Among these are Bergman & Klefsjö (2001), Ljungberg (2000), Dale (1999) and Montgomery (2001)

Used reference books are mainly the online editions of Nationalencyklopedin, but also Encyclopedia Britannica The use of two different Encyclopedias will

guarantee that the correct explanation of the search word is used in doubtful cases The literature was found by web search in the catalogues, CHANS, at the library at Chalmers University of Technology, Gothenburg and LUCIA, the library catalogue

at Luleå University of Technology, Luleå Some references were found from previous works of the authors and from tips and advices from colleagues and friends and a few references were also available at the Cage Factory

2.4 Choice of data collection method

According to Wiedersheim-Paul & Eriksson (1991) and Arbnor & Bjerke (1994) the data collected in the research can be of two kinds:

− Primary data: This is new information that the research team has to collect

− Secondary data: This is information, already gathered by someone else, which

can be used in the research

Wiedersheim-Paul & Eriksson (1991) mean that it is often appropriate to use secondary data at the beginning of the research because it is easier and cheaper According to Yin (1994) data for case studies can come from six sources: documents, archival records, interviews, direct observation, participant-observation and physical artifacts

2.4.1 Primary data

A basic method to find what people are experiencing is to ask them This can be done by a standardized interview or by a questionnaire The possibility to adjust the questions to a single individual is important Qualitative interviews of this kind are

called in-depth interviews (Wallén, 1993)

Holme & Solvang (1991) argue that the strength with the qualitative interview is that the interview situation is similar to an everyday situation or conversation

In depth interviews were carried through with a TPMG5 Manager, a TPMG Coordinator at the Cage Factory, a Quality Assurance Manager and a Professor in Quality Engineering at Chalmers University of Technology The purpose of these interviews was to get information about the existing TPMG approach, a group view

of Six Sigma and its future in SKF and to get an external point of view about Six Sigma, which also will secure the validity of the thesis (see Section 2.6.1)

An interview was also made with a Master Black Belt at Volvo Cars Engine in Skövde This was done in order to benchmark the experiences of their Six Sigma venture

According to Holme & Solvang (1991) a group interview or group discussion is similar to any other form of interview The basic difference is the social dimension added between the participants

The authors have also collected primary data by putting together a focus group with four white-collar workers in the Cage Factory The discussed topic was: "how can Six Sigma be implemented in the Cage Factory?" The evaluation of the DMAIC project together with the Improvement Group was done in a similar manner

The interviews and focus group were semi-structured since the authors prepared questions or topics for discussion in advance The questions were of a more open nature to invite the interviewee to respond with his or her own words

Primary data in the DMAIC project was gathered by the use of selected tools at different stages in the DMAIC methodology Such tools are Process Mapping, Pareto Charts, Cause-and-Effect Diagram, Check Sheets, Process FMEA and Tree Diagrams, described closer in Chapters 3 and 4 These tools were used in the improvement group assembled to deal with the quality shortages in the turning device Beside the two authors, the group consisted of two operators, a production technician, a tool technician and a quality engineer The authors prepared the use of these tools by studying them in advance and then acting as supervisors as well as team members The authors mapped the turning process by directly observing the process

The authors also performed a measurement of defective cages after the turning activity in Production Channel 13 during a three-week period This was done by designing a form that enabled the operators to specify the number of defects (rework or rejected) and the type of defects for the different types of cages

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The authors have decided to abbreviate Total Process Management as TPMG (TPM Gothenburg) to distinguish between Total Productive Maintenance and the local TPMG at SKF

Shorter, unstructured interviews and conversations were also carried out with technicians and operators who are familiar with the processes and the turning problems

An interview with a controller of the Cage Factory was done to gather information about costs concerning the DMIAC project In order to get information about costs

to the customer when complaints occur, the authors also interviewed production technicians in an assembly channel, a customer to Production Channel 13

2.4.2 Secondary data

Secondary data in the improvement project was collected from internal complaint

records and files from the SPC software SPC Light, which gives information about

the capability in the channel studied

Data, in form of downtime for Channel 13, was gathered from the automatic production monitoring system (D-Log)

The authors have been able to collect information about the current TPMG initiative in the Cage Factory by reviewing internal documents at SKF

Also, thanks to SKF, some information was gathered from SKF websites, annual reports and company internal documents describing work approach and economical numbers Information was also gathered within the company from conversations with employees

2.5 Methodology and chosen tools in the DMAIC Project

As mentioned previously the authors use Six Sigma methodology DMAIC (discussed thoroughly in Section 3.3) in the practical improvement project concerning the turning device

This paragraph will briefly motivate the tools chosen in the Six Sigma project Further descriptions can be found in Section 3.5:

− Project Charter: This tool clarifies the purpose and current status in the project The tool was also a way to ensure that the improvement team will meet the expectations from the sponsor

− Process Mapping: This tool gives an overview to the studied process and all members of the improvement team get a common view of the situation

− Pareto Chart: This tool brings out the most common reasons to problems and which problems are the most important to work with

− Frequency Study: This is carried out to get a better understanding of the scope

− Cause-and-Effect Diagram: This tool is helpful to find underlying causes of the problem It's easy to use and often gives appreciable results The tool was carried through with brainstorming and post-it notes

− Process FMEA: This tool detects potential problems but also gives these problems a priority number It's easy to use and some members of the team are already familiar with the tool from earlier projects in the organization

− Tree Diagram: This tool gives suggestions for measures to improve the current situation and also prioritizes them with respect to viability and efficiency The tool is carried through with brainstorming

− Matrix Diagram: This tool helps to prioritize among different measures by visualizing which measures that solve the different problems

These tools were chosen, because they were recommended in the literature for each specific phase However there are other tools that maybe would have been applicable in the different phases of the DMAIC project as well The authors don't claim that the tools chosen are the only or best mix, but they are suitable candidates

in the different phases Another reason was that the authors had some previous experience of the tools selected

2.6 Reliability and Validity

Independent of the choice of information gathering method, the information must always be critically reviewed in order to decide how reliable and valid it is (Bell, 1993)

2.6.1 Validity

Validity measures how well a certain approach will describe what was intended (Bell, 1993) Validity can be defined as a measurement instrument's ability to measure what it was designated for (Wiedersheim-Paul & Eriksson, 1993)

According to Holme & Solvang (1997) the validity will increase the closer you are

to who or what you are studying

The choice of the Case Study as research strategy provided the authors with the opportunity to be close to the organization studied and thereby increase the validity

By interviewing people both within and outside the organization the authors tried to get a balanced view of the situation and thereby strengthen the validity of the thesis

The authors' strategy when performing interviews was to try to prepare most questions in advance to be able to conduct the interviews in the same way with different interview issues This was also a way for the authors to make sure that the questions were valid and not drifted too far away from the purpose of the interview Also, after the interviews were carried through, the authors compiled summaries that were then sent to and confirmed by the interviewees This also increases the validity as well as the reliability

The fact that the tools chosen in the Six Sigma project did not demand an extensive previous training also increases the validity since the risk of misunderstandings by the team members will decrease The many different categories of professions in the assembled improvement group were also a deliberate action to strengthen the validity by getting many different points of view of the problem

2.6.2 Reliability

Reliability is a measure of to which extent a certain procedure gives the same result when applied under similar conditions at different occasions As an example, a specific question that gives one answer under certain circumstances and another answer under different circumstances is not a reliable question (Bell, 1993) Reliability aims to minimize errors and biases in a study (Yin, 1994)

If an instrument isn't reliable then there will also be a lack of validity A high level

of reliability does not necessary imply a high level of validity A question may give the same or almost the same answer at different occasions but still not measure what was designated (Bell, 1993)

To strengthen the reliability in the interviews, the authors used a tape recorder and took notes to reduce the possibility of errors in the interpretation of the interviews This was performed when the interviewee agreed to be recorded

To make sure that the interpretations and notes of the interviews were made correctly the authors sent the interviewees summaries of the interviews This gave them an opportunity to object to the content or make changes in the summary

To strengthen the reliability in the frequency study of the turning device the authors personally informed the operators on how the study was going to be made

3 THEORETICAL FRAME OF REFERENCE

This chapter presents the theoretical frame of reference to the reader Theories about Six Sigma, DMAIC and its tools and Total Process Management are reviewed The chapter intends to give the reader an insight into the theories that are the starting point for the empirical studies and the analysis in the following chapters

3.1 Six Sigma

Since this thesis will discuss the implementation of Six Sigma and the use of Six Sigma methodology it is necessary to present relevant theory about Six Sigma This section treats theory about the Framework, infrastructure, and implementation strategies in Six Sigma Also, critique to Six Sigma is presented

Pande et al (2000) give a definition of Six Sigma as follows:

"A comprehensive and flexible system for achieving, sustaining and maximizing business success Six Sigma is uniquely driven by close understanding and customer needs, disciplined use of facts, data, and statistical analysis, and diligent attention to managing, improving, and reinventing business process"

(Pande et al., 2000 p xi)

Pande et al (2000) mean that Six Sigma aims at a statistically calculated process target of 3.4 defects per million opportunities, dpmo According to Pyzdek (2003) companies traditionally have accepted that their processes perform at a level of three to four sigma, which translates to 6,200 to 67,000 dpmo

According to Six Sigma a manufacturing process with a normally distributed output

between process target and the closest tolerance limit and corresponds to a Process

3.1

6 The Greek letter sigma, σ, has its origin in Mathematical statistics and is used to describe variation (Pyzdek, 2003).

Low er

tolerance limit

Upper tolerance limit

Process variation 1.5 σ

Process target

A process operating on a Six Sigma level is producing 3,4 defects per million opportunities, dpmo.

Figure 3.1 Distance between target and tolerance limits if the process output is normally

distributed and performing at Six Sigma level The process mean is allowed to have a random variation of 1.5σ from the process target Source: Bergman & Klefsjö (2001 p.549)

Pyzdek (2001) means that Six Sigma is focusing on improving quality by helping corporations to produce better and cheaper products, faster

Pyzdek (2003) claims that there is a clear connection between which sigma level a company is operating at and the cost of poor quality Furthermore Pyzdek (2003) states that a company operating at a level between three and four sigma spends about 25-40 per cent of their annual turnover taking care of problems

However, a company operating at a Six Sigma level only spends about five per cent

of the turnover This relation is illustrated in Figure 3.2

3.1.1 The Six Sigma Framework

The corporate framework (Figure 3.3) of Six Sigma contains the four elements:

measurement system (Magnusson et al., 2003) The improvement projects are the core of the framework as they are, in a sense, the essence of Six Sigma (ibid)

Figure 3.3 The corporate Framework of Six Sigma, including the four main elements and the

core: Improvement projects Source: Magnusson et al (2003 p.33)

Launching Six Sigma in a company is a strategic decision that has to be taken by the Senior Management Without this, all other elements of the framework are meaningless Thus, the success of the Six Sigma initiative relies heavily upon the commitment of senior managers (Magnusson et al., 2003)

There are often standardized training courses that correspond to the different roles within the Six Sigma organization, from comprehensive courses for Black Belts to basic introductions to Six Sigma for White Belts (ibid)

All Six Sigma initiatives should also include a measurement system, providing consolidated measurement on process performance (ibid) Magnusson et al (2003) recommend using dpmo or alternatively the sigma metric for measuring process performance The corresponding dpmo and sigma values are presented in Appendix

1, Figure A.1

Stakeholder involvement implies that the vision of Six Sigma, variation reduction, methodologies and tools must be communicated to the customers, employees, suppliers and owners (Magnusson et al., 2003)

The core activity in Six Sigma is generating, executing and following up on improvement projects The four other elements in the framework only become valuable when they act as enablers for the improvement projects (ibid)

7

Magnusson et al (2003) include customers, employees, owners and suppliers in the definition of stakeholders

3.1.2 The Six Sigma Infrastructure

One of the most important issues at the beginning of a Six Sigma venture is defining the different roles required in the organization and also to clarify their different areas of responsibility When these decisions are made, factors like the goal with the venture, budget, existing staff and other resources have to be considered (Pande et al., 2000)

To make sure that the improvement activities have the necessary resources Six Sigma suggests the creation of a specific infrastructure In this infrastructure improvement and change activities become the full-time job for a number of employees in the company (Pyzdek, 2003 p.26-29)

According to Pyzdek (2003) the general Six Sigma change agents and their roles are:

− Champion and Sponsor: Champions are individuals in the high-level of the

organization that have an understanding and a commitment for Six Sigma In large companies a champion may be the Executive Vice President Sponsors are process and system owners who give a helping hand in initiating and coordinating Six Sigma improvement activities

− Master Black Belt: Master Black Belts provide technical leadership of the Six

Sigma program They possess the highest level of technical and organizational knowledge In addition to the knowledge of a Black Belt they might have a deeper understanding of the theory upon which the statistical methods are based

− Black Belt: Black Belts should master a wide range of technical tools for

problem solving Candidates may come from different disciplines but they do not need to be trained statisticians or analysts

− Green Belt: Green Belts are project leaders capable of managing Six Sigma

projects They receive training in a wide range of tools but to a less extent than Black Belts According to Magnusson et al (2003) the Green Belt role is suitable for middle managers, engineers, planners and supervisors for example, but also for operators interested in improvement work

− White Belt: Magnusson et al (2003) are also adding another hierarchy level

below Green Belts named White belts These individuals can participate in projects as team members They receive training about the Six Sigma philosophy and an overall view of applied tools

According to Magnusson et al (2003) a common guideline is to employ one Black Belt for every 100 employees, around 20 Green Belts for every Black Belt and one Master Black belt for every 20 Black Belts Standard training content for the different roles in the infrastructure is presented in Table A.1 in Appendix 1

The division of work in a Six Sigma project can vary among projects and different companies, but according to Pande et al (2000) a general Six Sigma project could

be run as shown in Figure 3.4

Master Black Belt

Black Belt, Green Belt

or Team leader Lead project to

success

Improvement Team

Analyze and Implement Improvement

Figure 3.4 Structure of a general Six Sigma project Source: Pande et al (2000 p.123)

3.1.3 Strategies for Six Sigma Implementation

Sanders & Hild (2000) argue that the news with Six Sigma is the packaging of quality tools, the focused problem-solving projects and also the attention to financial results and the sustaining of the gains made

According to Sanders & Hild (2000) there seem to be principally three categories

of deployment strategies for Six Sigma: "The Six Sigma Organization", "The Six

Sigma Engineering Organization" and "Strategic selection of individuals and projects" The differences between these three strategies and their strengths and

weaknesses are illustrated in Figure 3.5

Personnel trained:

A large part of the engineering staff

Personnel trained:

"Everybody" from senior

managers to individuals from

operations

Personnel trained:

Strategically selected individuals Informal leaders

Strengths:

− High level of awareness

− Common language

− A common set of tools

and the same approach

to problem solving

Strengths:

− Projects aligned with organizational objectives

− Less initial cost for training

− Flexibility in training content

− Strong project focus

− More attention to project application

− An inflexible road map

for problem solving

Possible Weaknesses

− Lack of common language across all areas

− Deployment outside operations and engineering is difficult

− Managers not provided training to integrate skills learned into everyday engineering responsibilities

Possible Weaknesses

− Isolation of those trained

− Lack of common language across all areas

− Difficult to integrate beyond "Six Sigma Projects"

− Tendency for an elitism attitude to develop

Figure 3.5 Strategies for Six Sigma implementation Source: Sanders & Hild (2000) p 303-309

Further, Sanders & Hild (2000) mean that there is no optimal strategy for all companies or even for all divisions or plants within a company

Gowen III (2002) argues that for successful implementation of Six Sigma programs, initiatives must be examined from a national culture perspective

high employee empowerment and high task orientation It demands a flexible and individualistic approach to Six Sigma, for employee self-expression and self-actualization

The employee empowerment approach is measured by the degree of delegation of significant decision-making authority, responsibility and accountability to workers

The task orientation approach is measured by the degree of specification of work goals, rules, methods and outcomes (Gowen III, 2002)

Many Six Sigma programs emphasize the importance of all employees' participation, from the single employee up to corporate management and stockholders In other programs important positions within the Six Sigma organization are emphasized In European Six Sigma Programs the importance of a single individual is toned down and instead the participation of everyone is emphasized (Bergman & Klefsjö, 2001)

3.1.4 Critique to Six Sigma

Companies in Europe have been more skeptical to Six Sigma, than companies in the USA, although there are successful examples like ABB and Volvo (Magnusson

et al., 2003)

There are many reasons why Six Sigma hasn't been as successful in Europe as it has been in the US Senior Managements in European companies have been suspicious to yet another quality improvement program Furthermore, there are aspects in the implementation phase of Six Sigma that works well in the US environment, but will be obstacles when implemented in European company culture and management style (Magnusson et al., 2003) But Pande et al (2000) claim that companies of different size and organizational structure can adopt Six Sigma:

"But it's also possible to "do" Six Sigma without making a frontal assault on your company culture"

(Pande et al., 2000 p xi.)

Not all Six Sigma programs succeed According to Magnusson et al (2003) this does not depend on the Six Sigma initiative itself but rather to such circumstances like unfamiliarity with improvement concepts, lack of commitment and cultural resistance

Critique to Six Sigma has been that it really doesn't consist of anything new that other methods don't already have Six Sigma only focuses on problems that have already occurred and doesn’t include any preventive measures (Andersson, 2003) Andersson (2003) argues that one reason why Swedish companies haven't adopted Six Sigma is the general recession and the companies are already living in a tough economical reality and don't have the energy to invest in a quality venture

3.2 The DMAIC improvement cycle

Many different improvement models have been applied to processes over the years Most of the models are based on the steps in the Plan-Do-Check-Act cycle, PDCA cycle, introduced by W E Deming (Pande et al., 2000 p.37)

Like many other models the DMAIC cycle is grounded in the original PDCA cycle (ibid) The main steps in the Six Sigma methodology, or DMAIC, are illustrated in Figure 3.6 The acronym should be interpreted as Define, Measure, Analyze, Improve and Control, which are symbols for the different phases in a Six Sigma project

Figure 3.6 The DMAIC methodology Source: Pyzdek (2003 p.4.)

A Six Sigma venture demands that the entire organization receives training in quality tools, which are frequently used within Six Sigma In many cases these tools have been known and used for decades (Pyzdek, 2003 p.237)

Magnusson et al (2003 p.62) gives an overview over the most commonly used tools in the DMAIC cycle, which they call the Seven-Times-Seven Toolbox, containing seven groups of improvement tools of seven tools each

The toolbox is presented in Appendix 2, Figure A.2 Master Black Belts and Black Belts should master a majority of the tools, while Green Belts and White Belts should be familiar with a selection (Magnusson et al., 2003)

3.2.1 How to choose a Six Sigma project

It is important to choose the right improvement project when working with Six Sigma Pande et al (2000) claim that a carefully chosen and well defined improvement project gives better and faster results According to Pande et al (2000 p.143) a successful Six Sigma project should fulfill three conditions:

1 There is a gap between current and desired performance

2 The cause of the problem is not identified

3 The solution to the problem is not predetermined, nor is the optimal solution known

The most commonly used sources for project generation are presented in Figure 3.7:

Supplier Problems

Possible Six Sigma Projects

Figure 3.7 The most commonly used sources for project generation Source: Magnusson et al (2003 p.57).

3.2.2 The Define Phase

The first step in the DMAIC improvement cycle is the Define Phase According to Pande et al (2000 p.239) this phase is important because it sets the foundation for a successful Six Sigma project by helping the user to answer four critical questions:

1 What is the actual problem to focus on?

2 What is the goal for the project?

3 Who is the customer to this process and what are the effects of the problem for the customer?

4 What is the process that is investigated?

Pyzdek (2003 p.239) adds to this list by suggesting that a current state map, future state, deliverables and due dates could be appropriable elements of the Define Phase

3.2.3 The Measure Phase

The second step in the DMAIC cycle is the Measure Phase According to Pyzdek (2003) this phase has the objective to measure the existing system or process and also to establish reliable and valid metrics to help steer towards the project goal defined in the Define Phase

Further, Pande et al (2000) mean that it is often difficult to decide what to measure This because of the many options available and that it is often strenuous

the project Often only one Y is studied to lower the risk of a lost focus in the project

For each identified Y a number of Xs, that might influence the Ys, have to be identified In reality there are two types of Xs, control factors and noise factors Control factors can be physically controlled, while noise factors are considered uncontrollable, too costly or not desirable to control (Magnusson et al., 2003)

To identify the Xs, Cause-and-Effect tools are often used, for example the Ishikawa Diagram It is usually good to detect as many Xs as possible from the start and then select the ones to be studied closer

The variation of the output in a process varies because of the embedded variation in the input factors to the process that will be transferred and summarized into the output, causing excess costs to the organization or its surroundings (Magnusson et al., 2003) This is illustrated in Figure 3.8

Figure 3.8 Variation in different input variables is transferred to characteristic of the output

Source: Magnusson et al (2003 p.16)

3.2.4 The Analyze Phase

The Analyze Phase of the DMAIC cycle is about becoming a process detective The use of tools in this Phase depends a lot on the process and the problem at hand (Pande et al., 2003)

Magnusson et al (2003) mean that if the use of improvement tools enables the identification of which of the input variables to a process affect the output, then it is relatively easy to come up with an improvement solution

Pande et al (2003 p.257) argue that there are two key sources of input to be able to determine the true cause of a problem:

− Data Analysis: The use of measures and data to reveal patterns or other

factors about the problem

− Process Analysis: A deeper investigation of the process to understand how

work is being done, which may help to find inconsistencies and problem areas that contribute to the problem

It is these two strategies combined that produce the real power of Six Sigma (ibid)

3.2.5 The Improve Phase

All the work in the Define, Measure and Analyze Phases will hopefully pay off in the Improve Phase This phase is about the generation, selection and implementation of solutions to the defined problem (Pande et al., 2003) Pyzdek (2003) argue that the Improve Phase is about being creative and to find ways to do things better, cheaper or faster

Pande et al (2000 p.276) list four questions that drive the Improve Phase:

− Can we come up with actions or ideas that will address the root cause of the problem and help us achieve our goal?

− Are any of these actions and ideas workable potential solutions?

− Which is the most cost-effective solution?

− Can we test the chosen solution to ensure that it really works and then permanently implement it?

3.2.6 The Control Phase

The final phase of the DMAIC cycle is the Control Phase This phase is about making sure that the made improvements last This is often done by modifications

of compensation and incentive systems, policies, procedures, budgets and other management systems (Pyzdek, 2003)

Once the solution has been implemented the process should be monitored to secure that the desired improvement targets have been achieved (Magnusson et al., 2003) Results and experiences from the improvement project need to be shared throughout the organization (ibid)

Pande et al (2000 p.344) give recommendations worth considering in the Control Phase:

− Develop good documentation to support the process

− Create measurement reports to supply information quickly and simply

− Develop plans to take care of problems that may arise in the future

− Keep documents active so that they don't become obsolete

3.2.7 Examples of tools in the different phases

One of the integral parts of Six Sigma is the use of tools within the DMAIC cycle Pande et al (2000 p.237) give some useful pointers when it comes to the use of tools:

− Never use a tool just because "we haven't done that one yet" There should always be a clear objective whenever a tool is chosen

− There are a variety of tools in the Six Sigma toolkit Hence, there are often several different tools that could be of possible help in the project Show carefulness in the choice you make

− Do not over-complicate things The complexity of the tool should match the given situation

− You may come up with your own variation of a tool as long as everybody can understand it and it doesn't contribute to the drawing of the wrong conclusions

− If a tool doesn't work, try something else

Pyzdek (2003 p.240) gives examples of commonly used tools in the different

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