chapter 2 literature survey -...
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CHAPTER 2
LITERATURE SURVEY
2. 1 INTRODUCTION
As mentioned on the previous chapter, the research work being
reported in this thesis was initiated on observing two kinds of researches and
practices that occur during the contemporary days. In the first kind of linking
Six Sigma with other strategies has found to support the organisations while
striving to face the increasing competition. In the other kind, ‘customer
voice’ adoption and translation have been given maximum thrust by the
researchers and practitioners. These kinds of developments induced the
author of this thesis to review the literature in three main directions. In the
first direction, the literature was surveyed to study the researches and
practices on Six Sigma concept. In the second direction, the literature was
surveyed to trace the history, development and application of QFD technique.
The literature on QFD was surveyed as it is the technique that is
predominantly adopted by the world community for customer voice adoption
and translation. In the third direction, the literature was reviewed to compare
Six Sigma and QFD from the perspectives of their researchers and practice.
The details of these works are presented in this chapter.
2.2 LITERATURE SURVEY ON SIX SIGMA CONCEPT
The literature world has been witnessing the emergence of plenty of
papers on Six Sigma. Brady and Allen (2006) have appraised this trend and
surveyed literature covering wide aspects of researches on Six Sigma. Some
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more authors have also reviewed papers on Six Sigma (Tannock et al 2007).
Hence, it was anticipated that an exhaustive literature survey on Six Sigma
would not only consume enormous amount of time and money but also would
overlap with some of the earlier reviews to a larger extent. In this context, it
was decided to review only the papers whose titles contained the term ‘Six
Sigma’.
The papers containing Six Sigma in their titles were collected from
Science direct (address: www.Scirus.com) and the databases maintained by
emeraldinsight (address: www.emerealdinsight.com), Springer (address:
www.Springer.com) and Interscience (address: www.interscience.wiley.com)
publishers were gathered. Few papers from inderscience (address:
www.inderscience.com) publishers were also downloaded. The total number
of such papers collected was 155. A preliminary reviewing of these papers
indicated that the following three issues are dominantly addressed in those
papers:
(i) Fundamentals of Six Sigma
(ii) Case studies on Six Sigma, and
(iii) Six Sigma in non- manufacturing arena
The rationale behind pinpointing these issues during this research work is
described in this section.
A considerable number of researchers have dealt exclusively the
fundamentals of Six Sigma concept (Kumar et al 2006). Particularly this kind
of papers was predominant during late 1980’s during which the evolution of
Six Sigma concept occurred. Later on, the Six Sigma researchers worked on
implementing it in real time situations and studied its outcome. Hence many
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researchers have reported the case studies on Six Sigma concept. After
making inroad into manufacturing sector, researchers have been examining
the working of Six Sigma concept in non-manufacturing arena (Chakrabarty
and Tan 2007). The statistics of these categories of research papers are shown
in Figure 2.1.
Figure 2.1 Statistics of Six Sigma papers
As shown in Figure 2.1, the papers dealing with case studies were
found to dominate the Six Sigma literature arena. In the following three
sections of this chapter, the contributions of the papers under the above three
categories of papers are briefly described.
2.3 FUNDAMENTALS OF SIX SIGMA
A careful overview of the papers dealing with the fundamentals of
Six Sigma revealed that, Six Sigma concept’s success is due to the two values
gained through its implementation. These values are ‘customer satisfaction’
and ‘financial gain’ (Snee 2004, Gowen III and Tallon 2005 and Miles 2006).
In fact, these two values are the main reasons for the rapid initial growth of
Six Sigma concept across the globe. The subsequent growth of Six Sigma
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concept occurred due to six factors. The characteristics of these six factors are
briefly explained in the following six subsections.
2.3.1 Adoption of Six Sigma by giant companies
Motorola, an American giant company, introduced the Six Sigma
concept in the year 1980 (Banuelas and Antony 2003, Tannock et al 2007 and
Kumar et al 2007). Because of the reputation of Motorola, other companies
like General Electric (GE), Allied signal, Eastman Kodak, Borg Warner
Automotive, and Honeywell implemented Six Sigma concept and gained
financial benefits (Henderson and Evans 2000, Kumar et al 2007, Kwak and
Anbari 2006 and Heuvel et al 2004). Subsequently other giant companies like
Ford and Dow chemicals, Bombaridier and Sony adopted Six Sigma concept
(Motwani et al 2004 and Kumar et al 2006). The adoption by these giant
companies is the one of the reasons for fast dissemination of Six Sigma
concept across the world.
2.3.2 Project based approach
TQM envisages the adoption of totality concept (Love et al 2000).
However, it will be near impossible to achieve higher degree of quality by
considering a large size company in total as one system. Contrary to this
concept, Six Sigma concept proposes project based approach which enables
the companies to achieve continuous quality improvement in increments
(Hoerl 2004 and Kwek and Anbari 2006).
2.3.3 Well defined continuous quality improvement approach
Every Six Sigma project is required to go through a well defined
procedure, which is shortly known as DMAIC (stands for Define, Measure,
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Analyses, Implement and Control). (Pande et al 2002, Tong et al 2004, Frings
and Grant 2005 and Heuvel et al 2004, Nonthaleerak and Hendry 2008,
Kumar et al 2008). This procedure enables every Six Sigma project to focus
towards achieving continuous quality improvement.
2.3.4 Training infrastructure
Although TQM proponents have been emphasizing the need of
training and education, their implementation has been lacking focus (Ho and
Wearn 1995). This deficiency is overcome in Six Sigma concept in which the
employees are systematically trained. They are designated as master black
belt, black belt, green belt and white belt employees (Snee 2004, Ingle and
Roe 2001, Su and Chou 2008 and Antony et al 2007, Nonthaleerak and
Hendry 2008).
2.3.5 Distinguishing features of Six Sigma concept from TQM
elements
Despite the emergence of some criticisms on Six Sigma concept,
time and again its power has been proved through the reported benefits.
Some critics claim that Six Sigma is same as TQM (Ingle and Roe 2001 and
Besterfield et al 2004). However the researchers like Motwani et al (2004),
Snee (2004) Andersson et al (2006) and Schroeder et al (2008) have indicated
the distinguishing differences between TQM and Six Sigma concept. The
main differences indicated by these researchers are pinpointed here.
Six Sigma concept envisages the engagement of the corporate
leaders in improvement processes whereas this aspect is not specifically
insisted in TQM. In Six Sigma concept, training is rigorous and its
infrastructure is highly defined. This is not so in the case of TQM wherein the
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training is generally imparted during the initial stage of its implementation.
In the case of TQM, quality data reporting is oriented towards customer
feedback and quality costs. In Six Sigma projects, the data collection exercise
is focused on customer and financial performance metrics. Thus the Six
Sigma researchers have not only established the distinguishing features of Six
Sigma, but also its superiority over TQM.
2.3.6 Current status of Six Sigma
The reviewing papers on Six Sigma concept from perspective of its
current status revealed the increasing growth of researches on linking Six
Sigma with design function, lean manufacturing and ISO 9000 based quality
systems (Bendell 2006, Pfeifer et al 2004 and Tang et al 2007). Another
aspect noticed is that, Six Sigma concept was introduced by a rich company
and hence its structure has been friendly to financially wealthy companies. In
order to make the Six Sigma concept suitable for all types of organizations,
modern researchers are exploring the ways and means of applying Six Sigma
concept in small and medium sized companies.
2.3.7 Hidden facts of Six Sigma growth
On the whole, the study of research papers on the fundamentals of
Six Sigma concept indicated that, its foundation lies on achieving customer
satisfaction and financial gain. Then its growth was characterized by the
construction of pillars like project based approach. Currently Six Sigma
concept spreads across the areas in which various strategies are employed to
achieve competitiveness. This aspect is shown in Figure 2.2.
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Customer Satisfaction
Succ
ess i
ngre
dian
t of S
ig S
igm
a
Proj
ect b
ased
app
roac
h
Infr
astru
ctur
e
Six Sigma with ISO 9000
Six Sigma for Small and Medium size Companies
Figure 2.2 Hidden facts of Six Sigma growth
2.4 CASE STUDIES ON SIX SIGMA CONCEPT
A bird’s eyeview on the literature arena would indicate that,
majority of current papers report numerous case studies on Six Sigma
implementation (Snee 2004 and Coronado and Antony 2002). It is somewhat
a unique feature, because in other fields, majority of the papers report
researches, which are either only analyzed or experimented in laboratories.
The researchers are trying to report the case studies presumably to convince
the theorists and practitioners about the practical and business significance of
Six Sigma concept. The papers appeared in this direction have reported the
case studies from numerous companies including Motorola and GE. Table
2.1 shows the research papers in which this kind of case studies have been
reported. The names of the companies about which these case studies have
been discussed in those papers are also indicated in this Table. The
contributions of these papers are highlighted in the following subsections.
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Table 2.1 Companies dealt in case studies on Six Sigma
implementation
Paper Companies in which case studies are carried out
Raisinghani et al (2005) Motorola, Allied Signal, GE, Our Lady of Lourdes
Motwani et al (2004) Dow Chemicals
Banuelas and Antony (2003) Multinational Companies –Name not specified
Thomas and Barton (2006) Orange Box
Henderson and Evans (2000) GE
Snee (2004) Newspaper companies - Name not specified
McAdam and Evans (2004) Seagate Technology UK
Basu (2004) Solectron factory, Sweden
Maleyeff and Kaminsky (2002) Laser drilling process in aircraft parts
Kumi and Morrow (2006) New Castle University Library, UK
Ehie and Sheu (2005) ABC Corporation
Holtz and Campbell (2004) Ford
O’ Neill and Duvall (2005) Name not specified.
Montgomery et al (2005) Arizona State University
Kumar et al (2006) Automotive Company
Sharma (2003) Baxer Battery
Banueles et al (2005) Film coating process industry
Koch et al (2004) Automotive Industry
Li et al (2006) Numisheet- Tokyo, Japan
Hsu et al (2007) Integrated circuit packaging factory
Sokovic et al (2005) Cimos foundry, Buzet, Croatia
Miles (2006) Johnson & Johnson,USA
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Table 2.1 (Contnued)
Paper Companies in which case studies are carried out
Su and Chou (2008) Semi conductor foundry, Taiwan
Schroeder et al (2008) Electronic component manufacturing company
Immaneni et al (2007) Capital One Banks
Craven et al (2006) Presbyterian Hospital, New York
Pandey (2007) MNC Bank
Frings and Grant (2005) Charleston Area Medical Centre
Heuvel et al (2004) Red Cross Hospital, Netherlands
Cook et al (2005) Virginia Tech
2.4.1 Flexibility of Six Sigma concept
A review of the papers enumerated in Table 2.1 indicated that, Six
Sigma concept is adopted by many organizations by making slight changes to
its original structure. This observation is supported by Motwani et al (2004).
They have referred literature to enumerate the different approaches of Six
Sigma adopted in six companies, which include Motorola, GE and Dow
chemicals. In line to this fact, Henderson and Evans (2000) have described
the differences in the Six Sigma approach followed by GE and Motorola.
This aspect indicates the flexibility of Six Sigma concept to allow deviation
for suiting the circumstances. However, the deviation in Six Sigma approach
is permitted as long as the concept allows only a maximum of 3.4 Defects Per
Million Opportunities (DPMO) (Linderman et al 2003 and Cook et al 2005).
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2.4.2 Tools and techniques deployed in Six Sigma projects
An important contribution of the papers reporting case studies are
the identification and enumeration of the tools and techniques employed while
implementing Six Sigma projects. Such tools and techniques indicated in
those papers are enumerated in Table 2.2.
Table 2.2 Tools and techniques used while implementing Six
Sigma projects
Name of the tool /technique used in Six Sigma projects
Papers
Pareto analysis
Thomas and Barton (2006), Snee (2004), McAdam and Evans (2004), Miles (2006), Banuelas and Antony (2003), Ehie and Sheu (2005), Pandey (2007), Cook et al (2005) and Banuelas et al (2005)
Cause and effect diagram
Snee (2004), Thomas and Barton (2006), Banuelas and Antony (2003), Kumar et al (2006), Taner et al (2007), Kumi and Morrow (2006), Cook et al (2005) and Basu (2004), Kumar et al (2008)
Cause and effect charts Schroeder et al (2008)
Histogram Miles (2006), Hsu et al (2007)
Run chart Banuelas and Antony (2003), Snee (2004) and Kumar et al (2006)
Control charts Ehie and Sheu (2005) and Maleyeff and Kaminsky (2002)
Statistical analysis Banuelas and Antony (2003), Thomas and Barton (2006) and Henderson and Evans (2000)
PDCA Cycle Craven et al (2006)
FMEA Kumi and Morrow (2006), Cook et al (2005), Su and Chou (2007), Schroeder et al (2008), Raisinghani et al (2005) and Banuelas and Antony (2003)
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Table 2.2 (Contined)
Name of the tool /technique used in Six Sigma projects Papers
Gamma distribution Hsu et al (2007)
Cause and effect matrix Banuelas et al (2005) and Sokovic et al (2005)
Process map Sokovic et al (2005), Basu (2004) and Banuelas and Antony (2003)
Regression analysis Kumar et al (2006), Akdag (2007)
Capability analysis Cook et al (2005), Raisinghani et al (2005) and Maleyeff and Kaminsky (2002)
Sampling plan Basu (2004)
Gap analysis Banuelas et al (2005)
Design of Experiments Koch et al (2004), Li et al (2006) and Raisinghani et al (2005)
Monto Carlo simulation Koch et al (2004)
Statistical process control Schroeder et al (2008), Cook et al (2005)
TRIZ Smith and Phadke (2005)
Measurement system analysis, Process control, Quality control charts
Raisinghani et al (2005)
T-test, Chi-square test, Scatter plot Henderson and Evans (2000)
Variational techniques, Process analysis
Tannock et al (2007)
Affinity diagram, QFD, Gantt chart, Stakeholder analysis,
Cook et al (2005)
Artificial Intelligence, Fuzzy logic, Neural net works
Patterson et al (2005)
ANOVA Kumar et al (2008)
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A careful overview of this enumeration indicates that, with the
exception of few techniques like measurement system analysis, all other tools
and techniques are already being used in TQM field (Pande et al 2002). This
superimposition leads to an impression that, Six Sigma concept is the
extension of TQM and hence, in a company implementing TQM, Six Sigma
concept could be easily implemented. However, the fact is not so, as
researchers have affirmed that certain ingredients are essential for
successfully implementing Six Sigma projects (Henderson and Evans 2000).
2.4.3 Success ingredients of Six Sigma projects
An interesting contribution of the papers reporting case studies is
the listing of the success ingredients of Six Sigma projects. This implies that
the researchers do not assume instant success of Six Sigma projects and rather
insist the practitioners to adopt precautious approach while implementing
them. In this direction, the enumeration of the success ingredients of Six
Sigma concept by Henderson and Evans (2000) is to be noted with interest.
They have enumerated the following as the success components of Six Sigma
implementation:
Upper management support/involvement
Organizational infrastructure
Training
Tools
Link to human resource development actions such as
promotions, bonuses etc.
Communication to the employees
Measurement systems and Information Technology (IT)
infrastructure
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Likewise, Basu (2004) has enumerated the following as critical
success factors for successfully deploying tools and technique in Six Sigma
projects.
Top management commitment
Availability of resources
Well designed education and training concept
Rigorous project management approach
McAdam and Evans (2004) have dealt with the following aspects of
successfully implementing the Six Sigma programme.
The role of management
Empowerment, reward and cooperation
To cap it all, Hahn (2005) has enumerated 20 aspects under the
terminology ‘key lessons learned’ as the success ingredients of Six Sigma
concept.
2.4.4 Limitations of Six Sigma concept
In parallel to the researches on success ingredients, some
researchers have investigated the limitations of Six Sigma concept. McAdam
and Evans (2004) have claimed that the Six Sigma concept is weak in
understanding what the customer wants and using the information for
subsequent product development. An important feature emphasized in this
paper is the need of implementing tools for successful implementation of Six
Sigma concept coupled with strategic change management process. In line to
this development, Motwani et al (2004) have presented a theoretical
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framework for Six Sigma implementation in which strategic initiative is
placed at its core.
2.4.5 DMAIC Approach
A striking coincidence noticed in the papers dealing with the case
studies on the Six Sigma concept is the use of DMAIC approach (Ehie and
Sheu 2005). This indicates that the DMAIC approach is a well-proven
improvement methodology in Six Sigma arena (Hwang 2006 and Tong et al
2004). Presumably due to this reason, the researchers have tried to improve
further the result of Six Sigma concept by keeping DMAIC approach as the
reference framework. For example, Ehie and Sheu (2005) have integrated
theory of constraints with DMAIC for achieving continuous quality
improvement. Likewise Yeh et al (2007) have integrated DMAIC with a
model called Fuzzy Linguistic computing model to evaluate the performance
of Supply Chain Management (SCM). More importantly, Edgeman et al
(2005) has emphasized the need of linking ‘Voice of Customer’ concept with
DMAIC. On the whole, these papers indicate the need of the technique,
which would have DMAIC as its framework and facilitate the strategic
change for achieving higher degree of customer satisfaction.
2.5 SIX SIGMA IN NON-MANUFACTURING ARENA
During the initial period of its emanation, the Six Sigma concept
entered only into the manufacturing arena. This is due to the reason that, the
models of Six Sigma contributed by Motorola, GE and Allied Signals are
impregnated with manufacturing practices. However on seeing the
tremendous financial gains reaped through the implementation of Six Sigma
projects, the captains of service industries have also been showing interest to
implement them in their arena (Antony et al 2007, Frings and Grant 2005 and
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Pandey 2007). However, the same framework of Six Sigma concept could
not be adopted in service industries. Rather certain modifications had to be
incorporated into the framework of Six Sigma concept that originated from
manufacturing companies (Hensley and Dobie 2005). These modifications
have been enabling the Six Sigma concept to stand erect on the foundations of
service industry essentials. In consequence to this development, frequently
papers reporting the application of Six Sigma concept in non-manufacturing
arena have been appearing in literature (Heuvel et al 2004). The contributions
of some of those papers are described in the following subsections.
2.5.1 Six Sigma in Healthcare Industry
Black and Revere (2006) trace the history of Six Sigma penetration
in healthcare industry. They have pointed out that, Six Sigma concept entered
into the healthcare organization around the year 2000. The penetration of Six
Sigma concept into healthcare industry was not very effective during the
initial years. However, currently many healthcare organizations have reported
the implementation of Six Sigma concept with high financial success. These
authors have named some service oriented companies like Mount Carmel
Health (Ohio), Scottsdale Healthcare (Arizona) and Virtual Health (New
Jersey), which have implemented Six Sigma concept and reaped financial
gains. Finally they have foreseen the future of applying Design for Six Sigma
and Lean Six Sigma concept in healthcare industries.
Papers like Sehwail and DeYong (2003), Frings and grant (2005),
Craven et al (2006), Kwak and Anbari (2006) and Revere et al (2004) have
also presented the examples of applying Six Sigma in healthcare
organizations. Among them, Sehwail and DeYong (2003), Revere et al
(2004), Frings and Grant (2005) and Craven et al (2006) have pointed out the
challenges of modifying Six Sigma framework for its successful application
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in healthcare industry. While carrying out this exercise, they have used the
DMAIC methodology. More recently, Taner et al (2007) have reported seven
cases of applying Six Sigma concept in health care industry. They have used
cause and effect diagram to depict the problems and causes handled during
the Six Sigma concepts executed in these cases. They have enumerated the
impediments to be overcome for successfully implementing Six Sigma
concept in health care industry in the future.
2.5.2 Six Sigma in Simulation and Software development fields
Mahanti and Antony (2005) have dealt with the application of Six
Sigma concept in simulation and software development fields. They have
pointed out the difference between software development and manufacturing
process. Particularly they have claimed that the software development is an
intellectual process whose visuability has to be ensured through
documentation. In order to implement Six Sigma concept in software field, a
tool kit and a set of techniques have been proposed by these authors. They
have also dealt with the ‘voice of customer’ and explained the features of
software QFD. Further they have compared the differences between the
Capability Maturity Model (CMM) and Six Sigma. They have indicated that
the CMM deals with the maturity of practices, whereas Six Sigma deals with
the maturity of result. In their research, they have tried to interlink DMAIC
methodology with simulation and software development fields. They have
pointed out that it is highly feasible to apply Six Sigma concept in simulation
and software development fields.
Patterson et al (2005) have applied Design For Six Sigma (DFSS)
in an automated decision System. They have employed DMAIC methodology
in their research. Hong and Goh (2003) have dealt with the application of Six
Sigma in software development. They have used the DMAIC methodology to
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design a Six Sigma framework for software development. They have also
compared the strengths and weaknesses of Six Sigma with an approach called
“Goal–Question–Measurement” (GQM) (Hong and Goh 2004). Finally they
have recommended the synergizing of Six Sigma and GQM for reaping the
outstanding fruitful results.
2.5.3 Six Sigma in Educational Service
A series of papers have emerged in the direction of applying Six
Sigma concept in educational service. Maleyeff and Kaminsky (2002) have
dealt with the introduction of Six Sigma concept in statistic education. Little
(2003) has dealt with the application of Six Sigma concept in improving the
quality of e-learning. He has cited the case of implementing Six Sigma
approaches in Tata group, which is one of the largest business organizations
of India. Mitra (2004) has pointed out the goal of educational institution in
disseminating Six Sigma concept into the society. He has also suggested the
curriculum for Six Sigma education.
Cook et al (2005) have described a course on Six Sigma concept
taught at Virgina Tech. They have also presented the outline of the Six Sigma
course. The feedback indicated that majority of the students are appreciating
the Six Sigma course. Similar exercise on conducting Six Sigma program at
Arizona State University has been reported by Montgomery et al (2005).
These papers have indicated the entry of Six Sigma concept in educational
arena. However the treatise in this regard by these authors has been minimal
and peripheral indicating the need of pursuing deeper research in this
direction.
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2.5.4 Success ingredients of Six Sigma in Service Industries
Knowles et al (2004) have presented a case study on applying
DMAIC methodology of Six Sigma concept in a United Kingdom (UK) based
confectionary plant. They have indicated the financial and non-financial
savings achieved through this exercise. Antony (2006) has presented a pilot
survey to assess the extent of Six Sigma application in the UK service
organizations. He has mentioned that, about 75 percent of the service
organizations that they have surveyed are implementing Six Sigma concept.
Some of the commonly used tools in these organizations are brainstorming,
process mapping and benchmarking. However it is surprising to note that,
QFD is one of the least commonly used techniques in these service
organizations. Throughout this article, the success ingredients of Six Sigma
concept are appraised. Two similar articles by Mahanti and Antony (2005)
and Antony et al (2007) also deal with the success ingredients of applying Six
Sigma in service organizations. These papers also highlight the benefits
reaped by several service organizations by implementing Six Sigma concept.
On the whole, the review of papers presented in this section has
indicated that the Six Sigma framework may be suitably modified and refined
to suit specific applications and nourish its inherent financial and non-
financial benefits. Further, the reviewing of these papers indicated that the
researches in this direction shall be started by keeping DMAIC methodology
as the foundation (Walters 2005).
2.6 LITERATURE SURVEY ON QFD
Being a technique that emerged during 1970s, a large number of
reports on QFD’s implementation have appeared in literature (Chan and Wu
2002). This trend even motivated few researchers to survey the adoption and
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the application of QFD. The most noticeable paper in this direction is Chan
and Wu (2002). These authors have reviewed as many as 650 research papers
covering wide areas of QFD applications and reported their findings. Hence,
any exhaustive survey on QFD will duplicate the majority of the works
reported by Chan and Wu (2002). Hence, the scope of the literature survey
reported in this section was restricted to the tracing of the growth of the QFD,
followed by identifying its application areas and recognizing its current trend.
The early researchers on QFD had concentrated to narrate its birth
and structure. All these researchers have mentioned that the development of
QFD is to be credited to Yogi Akao (1966) (Shen et al 2000a and Hunt and
Xavier 2003). Yogi Akao introduced QFD in the year 1966 which
subsequently found its application in Mitsubishi’s Kobe Shipyard in the year
1972 (Hunt and Xavier 2003, Bottani and Rizzi 2006). Thereafter the
implementation of QFD spread very fast across the world.
The early researchers had concentrated on sensing the power of
QFD. Particularly they have mentioned that QFD is a powerful tool in
converting customer voices into technically understandable languages (Akao
and Mazur 2003, Duffuaa et al 2003 and Politis 2003). They have also
pointed out that; the heart of QFD is the House of Quality (HOQ) matrix
(Kumar and Midha 2001, Braglia et al 2007). HOQ is the conglomeration of
many sub-matrices which are called as customer requirements matrix,
correlation matrix, relationship matrix, targets and goals (Duffuaa et al 2003,
Shahin and Nikneshan 2008, Almannai et al 2008). Soon researchers started
reporting the application of QFD in several types of industries. Some of the
papers are shown in Table 2.3.
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Table 2.3 Application of QFD in various types of industries
Paper Application of QFD
Lam and Zhao (1998) Teaching
Rahman et al (1999) Construction
Hwarng and Teo (2001) Higher education
Chan et al (2002) Distance learning program
Duffuaa et al (2003) Designing of Statistics course
Sahney et al (2004) Educational Institution
Korayem and Iravani (2008) Robotic System
Most of the researchers reporting the QFD implementation have
exclaimed the significant benefits achieved through the implementation of
QFD. Some of them are enumerated below:
Achievement of customer satisfaction
Prevention of future engineering changes
Acting as the linkage between several departments
Facilitating to benchmark the competitors’ performance
Identification of components for easy assembly and manufacturing
Despite the wide reporting of several kinds of the benefits like the
above, from 1990s, researchers began to point out certain drawbacks of QFD
(Buyukozhan et al 2007). Presumably to overcome these limitations,
researchers began to integrate QFD with other approaches and techniques.
Some of them are shown in Table 2.4.
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Table 2.4 Integration of QFD with other approaches and techniques
Paper’s Approaches/ technique
integrated with QFD
Shen et al (2000a) Kano’s model
Tan and Pawitra (2001) Serve QUAL and Kano’s model
Sahney et al (2004) Serve QUAL
Pramod et al (2006) Total Productive Maintenance
Shen et al (2000b), Kumar et al (2006) Benchmarking
Kwong et al (2007), Buyukozhan et al (2007) Fuzzy set theory
Shahin and Nikneshan (2008) Customer relationship management
Almannai et al (2008) FMEA
Ho (2008) Analytical hierarchical process
Further, in this direction of research, some authors have contributed
improved and extended models of QFD. A review of those models would
indicate that, TQFD is the model that overcomes many commonly cited
limitations of QFD (Devadasan et al 2006 and Kathiravan et al 2008).
Particularly it is stated that the application of QFD becomes difficult when the
volume of data being introduced in it is becoming excessively high. This
difficulty is overcome by TQFD by splitting the matrices of HOQ and
progresses through five stages.
TQFD starts with development of customer requirement matrix and
ends with work instructions. A QFD project ends by specifying the targets for
reacting to the customer voices in HOQ. However, the exact actions to be
taken for reacting in response to the customer voice are not explicitly derived
in a QFD project. This deficiency is overcome in the case of TQFD by
evolving work instructions. Work instruction indicates the actions to be taken
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by the personnel working in the place of work for reacting to the concerned
customer voice. In this background, during this research, TQFD was
considered as a prudent technique for the integration with Six Sigma.
2.6.1 Six Sigma and QFD: A comparative view
In comparison to QFD technique, the age of Six Sigma is shorter.
QFD emerged in the year 1966 (Duffuaa et al 2003 and Politis 2003), while
Six Sigma emerged during 1980’s (Tannock et al 2007 and Kumar et al
2008). However, the rate of growth of Six Sigma application has been higher
than that of QFD. QFD is found to be applicable in both large and smaller
organizations. However, Six Sigma finds its application only in large and
richer companies like General Electric (GE); Honey well, Motorola and
Allied Signal (Su and Chou 2008). Despite these differences, the growth
pattern and the current development status of both Six Sigma and QFD are
similar to each other.
During the initial period of its emanation, the researchers were
trying to define Six Sigma and ascribe its characteristics. A summary of
definitions on Six Sigma can be seen in papers like Chakrabarty and Tan
(2007). In a nutshell, these researchers have indicated that Six Sigma is a
disciplined methodology making use of statistical data to solve the problems
by adopting project approach and imparting vigorous training to the personnel
associated with it (Pandey 2007). All the researchers have pointed out that
Six Sigma progresses through two pillars. These pillars are called as DMAIC
‘improvement methodology’ and ‘belt system based training’. According to
the DMAIC improvement methodology, a Six Sigma project has to progress
through five phases namely Define, Measure, Analyze, Improve and Control
(Pande et al 2002, Tong et al 2004, Frings and Grant 2005, Heuvel et al 2004
and Tannock et al 2007).
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According to the belt system of training, the team members of a Six
Sigma project, are imparted training and given the designations as white belt,
green belt, black belt, master black belt and champion (Antony et al 2007). In
many companies implementing Six Sigma, the training with these
designations is integrated with the remuneration and incentives of the
associated employees (Park 2003).
Like in the case of QFD, during the earlier years of its emanation,
Six Sigma was applied largely in manufacturing companies (Snee 2004 and
Coronado and Antony 2002). Later on, its implementation was extended to
other industries. Particularly during the recent years, the implementation of
Six Sigma in service industries is noted with interest (Mahanti and Antony
2005 and Antony et al 2007).While extending its implementation to the
industry other than manufacturing, the methodology of implementing Six
Sigma has been suitably reoriented to fit to the type of industries in which it is
implemented. However, the two pillars of Six Sigma have not been altered.
This indicates the flexible nature of Six Sigma concept.
Like in the case of QFD, the literature on Six Sigma also witnesses
the emergence of extended models. Some of them are lean Six Sigma and
DFSS (Besterfield et al 2004). Six Sigma makes use of several TQM
techniques (Besterfield et al 2004). However, despite several commonalities
of its objectives and growth pattern, QFD does not find its authentic place in
Six Sigma projects.
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2.7 CONCLUSION
Although there have been few criticisms on Six Sigma concept, its
creditability has been well established and reported widely in literature
(Kumar et al 2006, Motwani et al 2004 and Hensley and Dobie 2005).
Particularly, its capability in bringing out financial gains is viewed with
interest by the practitioners. Besides, the world community has nourished
numerous other benefits by implementing Six Sigma concept (Tong et al 2004
and Schroeder et al 2008). The literature survey reported in this chapter
delineated certain interesting developments occurring in research and practice
arena. First of all, the review of these papers indicated the expanding domain
of Six Sigma. Particularly its scope of application has been extended from
manufacturing arena to service industry. Among all, its entry into the
healthcare industry is noted with interest (Sehwail and DeYong 2003). At the
same time, the Six Sigma researchers have proved that the integration of Six
Sigma with other strategies lead to synergic power (Arnheiter and Maleyeff
2005).
Amidst these developments, it is surprising to note that only
minimum interest is shown in practical and research arenas towards applying
QFD technique in Six Sigma concept. This is despite the fact that QFD has
spread to majority of the geographical parts of the world and fields (Chan and
Wu 2002). At the same time, the field of QFD has been witnessing the
emergence of its improved versions. These improved versions have made the
QFD application easier and specific to the applications. In this background,
during this research work, the TQFD technique was adopted (Devadasan et al
2006). During this research, TSSFD technique was designed by linking TQFD
technique with Six Sigma concept.