chaptershodhganga.inflibnet.ac.in/.../10603/35278/9/09_chapter1.pdf · 2018. 7. 2. · and...
TRANSCRIPT
Chapter 1
1
Chapter: 1
INTRODUCTION AND SUMMARY OF THESIS
1.1 Introduction
Statistics plays a vital role in analysis and decision making in all spears of life.
Researchers in the field of engineering, management, social sciences etc. also use statistics
heavily in their data analysis and make meaningful conclusions. In industrial scenario, as
competition grows every day, it is a challenge for the organizations to survive in the
market. The customers have greatly increased their quality requirements, and this trend is
likely to be intensified by competitive pressures in future.
Generally, all the industrial processes starts from identifying customer requirements
and end with delivery of product or service to the customer. At each stage of this product
or service realization process, there are always challenges and opportunities which can be
explored for further improvement, so that organizations can be more competitive and
successful in the market. Statistical analysis of process/ product/ market related data help
the organizations to succeed in this endeavour.
One objective of this research is to study application of various statistical
techniques at different stages of the organizational processes for performance improvement
in Indian industries. The success of an organization depends on how well it takes care of
the entire stream of activities starting from identifying customer demand to delivering of
products/ services to customers. If any failures occur anywhere in this value stream, the
organization will not be able to survive in the market. Hence identifying the weak areas in
Chapter 1
2
the process and improving them are at most important for every business organization.
During this study, few important processes from various organizations were selected. The
processes considered for study includes demand forecasting, product design, reliability
analysis, production and engineering process optimisation etc. Methods like Six Sigma,
Taguchi method, Time series forecasting, Reliability analysis and other statistical tools
were considered during this research. The systematic introduction of these methods marks
the start of substantial improvement in quality, productivity and customer satisfaction,
thereby improving the profitability and competitiveness of the organization.
The remaining part of this chapter is arranged as follows. Section 1.2 presents a
basic concepts and literature review and on Six Sigma, Taguchi methods, Time series
forecasting and Reliability. Section 1.3 provides the overview of this thesis followed by list
of publications/ presentations related to this research in section 1.4.
1.2 Basic concepts and literature review
1.2.1 Six Sigma methodology
In the attempt to manage change, many large organisations have pursued formalised
change programmes or quality initiatives such as Six Sigma that can have a significant
impact on the bottom-line and working culture of an organisation. The Six Sigma
methodology is becoming one of the most successful quality management initiatives
(Gutiérrez et al, 2012). This methodology is a breakthrough business strategy used for
quality and process improvement by using a set of structured tools and statistical measures
to evaluate processes (Adams et al, 2003). Six Sigma is a disciplined, project-oriented,
statistically based approach for reducing variability, removing defects and eliminating
Introduction and Summary of Thesis
3
waste from products, processes and transactions (Montgomery and Woodall, 2008). Six
Sigma can facilitate in solving complex cross functional problems where the root causes of
a problem are unknown and help to reduce undesirable variations in processes (Breyfogle,
2003). It really takes Total Quality Management (TQM) efforts to the next level and has a
great future even in services (Lazarus and Butler, 2001). It creates a sense of urgency by
emphasizing rapid project completion, typically within six months. Motorola introduced
the concept of Six Sigma in the mid 1980s as a powerful business strategy to improve
quality. It has been claimed to be the best known approach to process improvement (Snee
and Hoerl, 2003). Leading organizations with a track record in quality have adopted Six
Sigma and claimed that it has transformed their organization (Bisgaard and Freiesleben,
2004).
The Six Sigma approach starts with a business strategy and ends with top-down
implementation, having a significant impact on profit if successfully deployed (Adams, et
al, 2003; Mahesh et al, 2006). It takes users away from ‘intuition based decisions’, to ‘fact
based decisions’ (Ellis, 2001). Many papers and books have discussed Six Sigma – the
concept, its ingredients, its relation to other quality concepts and its benefits, its
weaknesses etc. Articles/ books are also available in topics related to: What is Six Sigma?
(Harry, 1997; Harry and Schroeder, 2000; Halliday, 2001); Why do we need Six Sigma?
(Pande et al., 2000); What makes Six Sigma different from other quality initiatives? (Snee,
2005); Six Sigma deployment (Keller, 2001); Six Sigma and bottom line (Bisgaard and
Freiesleben (2004); Is Six Sigma really different? (Walters, 2005); Does Six Sigma
improves performance? (Foster, 2007) Critical success factors of Six Sigma
implementation (Treichler, 2005); Hurdles in Six Sigma implementation (Hahn, 2005); Six
Chapter 1
4
Sigma project selection (Pande et al., 2003); Organisational infrastructure required for
implementing Six Sigma (Snee and Hoerl, 2003; Taghizadegan, 2006; Treichler, 2005);
Integrating many facets of Six Sigma (De Mast, 2007) etc. In the later part of 2000, there
were efforts to integrate Six Sigma with various other initiatives/ methodologies. These
include integration of Six Sigma with Lean management (Smith, 2003; Ferng and Price,
2005; Shah et al, 2008; Chen and Lyu, 2009; Chen et al, 2010), Knowledge management
(Gowen et al, 2008), Industrial engineering (Bunce et al, 2008), ISO 9001:2008 (Karthi et
al, 2011), Manufacturing executing systems (Hwang, 2006) etc.
In Six Sigma, broadly two approaches are used – DMAIC (Define-Measure-
Analyze-Improve-Control) and DFSS (Design for Six Sigma). DMAIC is used mostly for
existing processes (Firka, 2010). This approach not only makes use of Six Sigma tools, it
also incorporates other concepts such as financial analysis and project schedule
development (Bisgaard and Freiesleben, 2004). The DMAIC methodology is excellent
when dealing with an existing process in which reaching a defined level of performance
will result in the benefits expected (De Mast, 2007). Six Sigma has been embraced by
companies not only for its robust tool set but also because of its well-defined application
methodology, the DMAIC. When a new process is required, DFSS is used. DFSS consists
of a number of disciplined and rigorous approaches to product, process, and service design
(El-Haik and Roy, 2005). Both DMAIC and DFSS approaches integrates a set of tools and
techniques in a disciplined fashion (Kumar et al., 2006).
The first phase in a DMAIC project is define phase. This phase of the DMAIC
methodology aims to define the scope and goals of the improvement project in terms of
customer requirements and to develop a process that delivers these requirements. The first
Introduction and Summary of Thesis
5
step towards solving any problem in Six Sigma methodology is by formulating a team of
people associated with the process. The team consists of a leader (generally known as
Black Belt) and few members (Green Belt). The primary responsibility of team members
was supporting the Black Belt in executing the project related actions. A person from the
management, termed as Champion, monitors the progress of the project during its
execution. For providing training and giving guidance for completing the project, the
support of a Master Black Belt (MBB) is used. The team first prepares a project charter
with all details of the project. This will help the team members clearly understand the
project objective, project duration, resources available, roles and responsibilities of team
members, project scope and boundaries, expected results from the project etc. This creates
a common vision and sense of ownership for the project, so that the entire team is focused
on the objectives of the project (Park, 2002). After the project charter, a Supplier-Input-
Process-Output (SIPOC) mapping is prepared. SIPOC is similar to process mapping for
defining and understanding process steps, process inputs and process outputs (Breyfogle,
2003). The team with the involvement of people working with the process prepared a
SIPOC mapping along with a basic flow chart of the process. This SIPOC has given a clear
understanding of the process steps needed to create the output of the process. Through this
exercise, the team got the clarity of the project in terms of the scope of the project, inputs,
outputs, suppliers and customers of the process.
The objective of the measure phase in a Six Sigma project is to understand and
establish the baseline performance of the process in terms of process capability or sigma
rating (Rahmqvist and Bara, 2010). During this phase data were collected on the critical to
quality (CTQ) characteristics and the baseline performance is evaluated. The purpose of
Chapter 1
6
analyze phase in a Six Sigma project is to identify the root causes that are responsible for
high variation in the selected CTQs. A brainstorming session was conducted to identify the
potential causes of high variation in the CTQs. The output of the brainstorming session
depends to a large extent on the quality and creativity of the session and the knowledge
level of the participants (Ishikawa and Lu, 1985; Imai, 1986).
Improve phase of a Six Sigma project is aimed at identifying solutions for all the
root causes selected during analyze phase, implementing them after studying the risk
involved in implementation and observing the results. The idea behind including the
control phase was to make sure that the benefits and knowledge generated from Six Sigma
projects are sustained on a long-term basis (Kumar et al, 2006). Sustainability of the results
requires standardization of the improved methods and introduction of monitoring
mechanisms for the key results achieved. It also requires bringing awareness among the
personnel performing the activities.
1.2.2 Taguchi method
In the 1980s, Dr. Genichi Taguchi received international attention for his ideas on
variation reduction, starting with the translation of his work published in Taguchi and Wu
(1979). Later on many publications were available with further illustrations in Taguchi
methods and its applications in industries. The publications that focused in this area were
Hunter (1985), Kackar (1985), Park (1996), Ross (1996), Taguchi et al (2000) etc. An
overview of different methods to achieve robust design is also provided by Park et al
(2006). Taguchi breaks down the design process into three stages: system design,
parameter design and tolerance design. According to the description in Taguchi (1986), in
system design different concepts and choices of technology are considered at different
Introduction and Summary of Thesis
7
levels. Parameter design aims at determining appropriate levels of parameters that result in
least sensitivity to sources of variation (Taguchi et al, 2000). Finally, in the last stage,
tolerances are set to further minimize the effects of noise factors (Taguchi, 1988).
Taguchi’s experimental design method is a well-known quality improvement
technique for carrying out the analysis of experiments with the least experimental effort
(Taguchi, 1988; Ross, 1996). It is also been widely used for process optimisation (Hossein
et al, 2010). This is due to the advantage of Taguchi’s approach, which includes
simplification of experimental plan by using orthogonal arrays as a basis of experiments,
and feasibility of interaction study between different parameters (Taguchi and Wu, 1979).
Fewer experiments imply that time and cost is reduced. This is extremely vital for any
industrial process where the cost involved is very high (Phadke, 1989).
Taguchi recommends use of the loss function to measure the performance
characteristic deviating from the desired value (Taguchi and Wu, 1979). The value of the
loss function is further transformed into a signal-to-noise (S/N) ratio (Phadke, 1989).
Usually, there are three categories of the performance characteristic in the analysis of the
S/N ratio, that is, lower-the-better, higher-the-better, and nominal-the-best (Ross, 1996).
Regardless of the category of the performance characteristic, the larger S/N ratio
corresponds to a better performance characteristic (Roy, 1990). The formula for calculation
of S/N ratio is defined as follows.
S/N 10 ∑ , for lower-the-better type
10 ∑ , for nominal-the-best type
10 , for larger-the-better type. (1.1)
Chapter 1
8
where Yi is the response measured during experimentation with average and standard
deviation s.
Around 1990s there was discussion on the statistical validity of methods proposed
by Taguchi. The articles published in this direction were Leon et al (1987), Box et al
(1988), Benton (1991), Shoemaker et al (1991), Box and Jones (1992), Myers et al (1992),
Goh (1993), Lucas (1994), Grize (1995), Ford (1996), Shainin and Shainin (1988), Scibilia
et al (2001), Robinson et al (2006a; 2006b) etc. Although many authors - for example,
Tribus and Szonyi (1989), Pignatiello and Ramberg (1991) and the contributors in Nair
(1992) - are critical to the statistical methods advocated by Taguchi, they give him credit
for his work on communicating the importance of reducing variation to industry. Quite a
few publications are available describing alternate methods for achieving robustness or
extending the scope of application of the methodology. The publications available in these
directions are Vining and Myers (1990), Chan and Xiao (1995), Engel and Huele (1996),
Andersson (1997), Borkowski and Lucas (1997), Box and Bisgaard (1998), Myers and
Montgomery (2002), Lee and Nelder (2003), Myers et al (2004), Myers et al (2005), Smith
and Clarkson (2005) etc.
1.2.3 Time series forecasting
Time series analysis and its application in generating forecasts have become
increasingly important in various fields of research, such as business, economics,
engineering, medicine, and others. The forecaster uses past data to build a model that
explains the behavior of specific variables. This model is then used to make the statement
about the future on the assumption that the future will be like the past (Stekler, 2007). De
Gooijer and Hyndman (2006) have surveyed the development of time series models over
Introduction and Summary of Thesis
9
the past 25 years. They explain that each and every particular time series method works,
primarily because it is based on solid statistical foundations. A wide variety of models,
varying in the complexity of functional form and estimation procedures, has been proposed
for forecasting. They include; multiple regression, decomposition, exponential smoothing,
auto regressive (AR), moving average (MA), auto regressive moving average (ARMA),
auto regressive integrated moving average (ARIMA), neural networks etc models (Box et
al, 2008; Weckman et al., 2008).
Auto Regressive Integrated Moving Average (ARIMA) models have been studied
extensively by Box and Jenkins (1970), and their names have been synonymous with
general ARIMA process applied to time series analysis and forecasting. The Box and
Jenkins (1970) define a general multiplicative seasonal ARIMA model in the form:
Φ Θ (1.2)
where,
B is the backward shift operator, ϕ ,Φ , θ ,Θ are polynomials of order
, , , respectively, denotes a purely random process (Bowerman and O’Connell,
1993).
Φ 1 … (1.3)
where, αi , i = 1, 2, … are constants.
Chapter 1
10
The variables are formed from the original series not only by simple
differencing (to remove the trend) but also by seasonal differencing, , to remove the
seasonality. For example, if 1 and 12, then,
The model stated above is said to be a seasonal ARIMA model of order
. The values of and do not usually need to exceed one (Montgomery
et al., 2008).
1.2.4 Reliability modeling
In industrial life testing and medical survival analysis, it is very common that the
object under study or observation is lost or withdrawn before failure or the life time of the
object is only known within an interval. Data obtained from such experiments are called
censored data (or an incomplete data). Reducing the total test time and the associated cost
is one of the major reasons for censoring. A censoring scheme, which can balance between
total time spent for the experiment; number of units used in the experiment; and the
efficiency of statistical inference based on the results of the experiment, is desirable. The
most common censoring schemes are type-I censoring and type-II censoring. Under type-I
censoring, the testing is continued until a pre-specified time point. In type-II censoring, the
testing is continued up to a pre-specified number of failures (Nelson, 1982). However, the
conventional type-I and type-II censoring schemes do not have the flexibility of allowing
removal of units at points other than the terminal point of the experiment. Because of this
Introduction and Summary of Thesis
11
lack of flexibility, a more general censoring scheme called progressive censoring was
introduced. In the progressive censoring scheme, the tested items are allowed to be
withdrawn at some other times before the end of life testing (Balakrishnan and Aggarwala,
2000). A properly planned progressively censored life testing experiment can save both the
total test time and the cost induced by failure of the units and increase the efficiency of
statistical analysis.
Aggarwala (2001) introduced type-I interval and progressive censoring scheme and
developed the statistical inference for the exponential distribution based on progressively
type-I interval censored data. Ng and Wang (2009) discussed statistical inference for
Weibull distribution under progressive type-I interval censoring. They have compared
different estimation methods for the parameters of Weibull distribution via simulation.
Chen and Lio (2010) considered parameter estimation for generalized exponential
distribution under progressive type-I interval censoring. They have obtained maximum
likelihood estimate of unknown parameters using EM algorithm, midpoint approximation
methods and method of moments. Huang and Wu (2008) considered determination of
reliability sampling plan under progressive type-I interval censoring using cost function.
Lin et al (2009) considered determination of optimum life testing plan with progressively
type-I interval censored data from the log-normal distribution.
1.3 Methodology and objectives of the study
Exploring application of various statistical techniques for improving the quality and
performance of processes in Indian industries for enhancing the customer satisfaction was
the objective of this research. Towards this endeavour, existing process improvement
Chapter 1
12
methods available in literature were studied first. Based on this information, an attempt
was made to address various process problems of different Indian industries. The processes
considered for study includes demand pattern of customers, product design, product
manufacturing, reliability estimation etc. The main objectives of the current research work
are as follows.
• To study the effectiveness and shortcomings during implementation of Six Sigma
methodology in Indian industries.
• To understand and study the practical application of Taguchi method for product
design and process optimization.
• To evolve a general approach for problem solving in small and medium size
organizations where systematic approaches like Six Sigma and TQM were not
practiced.
• To explore the feasibility of application of time series forecasting in the demand
pattern of organizations.
• To estimate the parameters of well known probability distributions under
progressive type-I interval censoring scheme.
1.4 Thesis at a glance
The main objectives of the present research are to study application of various
statistical techniques at different stages of the organizational processes for improvement in
Indian scenario. This thesis consists of six chapters. Chapter 1 contains the introduction,
basic concepts with literature review, objectives, chapter-wise overview and list of
publications in journals/ conferences.
Introduction and Summary of Thesis
13
In Chapter 2, the effectiveness of implementation of Six Sigma methodology for
improving the processes and its shortcomings are considered. This methodology was tried
for organizations varying from manufacturing, engineering, services and non-conventional
energy to healthcare. Integration of techniques like Beta correction along with Six Sigma
methodology was also discussed during this study. Six different applications of the
methodology are demonstrated in this chapter. The discussions of this chapter are based on
the articles, Gijo and Scaria (2010; 2013b), Gijo et al (2011), Gijo et al (2013), Gijo and
Antony (2013) and Gijo and Sarkar (2013). Information on Six Sigma projects from
various organizations was gathered during this study. The shortcomings in Six Sigma
implementation under Indian scenario were identified through these projects. The
weaknesses in project selection, defect definition, conduct of training, validation of causes,
sustainability of results, estimation of project benefits etc are discussed in this chapter. The
recent articles, Gijo (2011) and Gijo (2012) are based on the results of this study.
Chapter 3 explains the details of Taguchi method and its applications in product
design, process optimisation and improvement. Taguchi’s robust parameter design concept
was used to design products to achieve consistent level of performance. Three different
areas of application of Taguchi methods are discussed in this chapter. Two of these
applications are related to product design and the third one is related process optimization.
These cases have reinforced the applicability of Taguchi method in industrial scenario and
are published in Gijo and Scaria, (2011, 2012), Acharya, Gijo and Antony (2010).
Chapter 4 presents the approach for general problem solving in industry. These
were applied in small and medium sized industries in India where they were not able to
implement approaches like Six Sigma and TQM due to many organizational constraints.
Chapter 1
14
Three different problems in various industries are selected and the problem solving
methodology was demonstrated with good results. In this case, quite a few statistical
techniques were logically linked to arrive at solutions for process problems. The recent
work, Gijo and Scaria (2013a) along with early works Gijo (2005) and Gijo and Perumallu
(2003) were based on this approach of problem solving.
Every organization plan its activities based on the projected demand for its products
and services in future. Hence, organizations adopt different types of forecasting models to
predict the demand from the market. Chapter 5 explains the forecasting of monthly demand
of products based on Box Jenkin’s seasonal autoregressive integrated moving average
(SARIMA) models. The results are available in Gijo (2011).
In Chapter 6, we estimate the parameters of lognormal distribution based on
progressive type-I interval censored data. Since the maximum likelihood estimates (MLEs)
were not obtained in a closed form, the expectation-maximization (EM) algorithm, mid-
point approximation and method of moments were used to obtain the estimates. The
Bayesian estimates also were tried with Lindley’s approximation and Metropolis-Hastings
algorithm. A real life data analysis also is demonstrated in this chapter.
Thus, the thesis explores various applications of statistical techniques for improving
the business processes in Indian industry. The results of these studies have been published
or communicated to leading international journals.
1.5 Publications/ presentations
The results of the thesis have been published/ presented/ communicated in the form
of research papers as listed below.
Introduction and Summary of Thesis
15
1.5.1 Papers in journals
1. Acharya, U. H., Gijo, E. V. and Antony, J. (2010). Quality engineering of a traction
alternator by robust design, Proceedings of the Institution of Mechanical Engineers,
Part B: Journal of Engineering Manufacture, 224(2), 297-304.
2. Gijo, E. V. (2005). Improving process capability of manufacturing process by
application of statistical techniques, Quality Engineering, 17(2), 309-315.
3. Gijo, E.V. (2011). 11 ways to sink your Six Sigma project, Six Sigma Forum
Magazine, 11(1), 27-29.
4. Gijo, E.V. (2011). Demand forecasting of tea by Seasonal ARIMA model,
International Journal of Business Excellence, 4(1), 111-124.
5. Gijo, E.V. (2012). Shortcomings in Six Sigma implementation: an experience in
Indian industries, Science & Society, 10(2), 109-116.
6. Gijo, E.V. and Antony, J. (2013). Reducing patient waiting time in outpatient
department using lean six sigma methodology, Quality and Reliability Engineering
International, (wileyonlinelibrary.com) DOI: 10.1002/qre.1552.
7. Gijo, E.V., Antony, J., Hernandez, J. and Scaria, J. (2013). Reducing patient
waiting time in a Pathology department using the Six Sigma methodology,
Leadership in Health Services, 26(4), (in press).
8. Gijo, E.V. and Perumallu, P.K. (2003). Quality improvement by reducing variation:
a case study, Total Quality Management & Business Excellence, 14(9), 1023-1031.
9. Gijo, E.V and Rao, T.S. (2005). Six Sigma implementation - hurdles and more
hurdles, Total Quality Management & Business Excellence, 16(6), 721-725.
Chapter 1
16
10. Gijo, E.V. and Ravindran, G. (2008). Quality in the construction industry: an
application of DOE with goal programming, Total Quality Management & Business
Excellence, 19(12), 1249-1255.
11. Gijo, E.V. and Sarkar, A. (2013). Application of Six Sigma to improve the quality
of the road for wind turbine installation, The TQM Journal, 25(3), 244-258.
12. Gijo, E.V. and Scaria, J. (2010). Reducing rejection and rework by application of
Six Sigma methodology in manufacturing process, International Journal of Six
Sigma and Competitive Advantage, 6(1/2), 77-90.
13. Gijo, E.V. and Scaria, J. (2011). Application of Taguchi method to optimise the
characteristics of green sand in a foundry, International Journal of Business
Excellence, 4(2), 191-201.
14. Gijo, E.V. and Scaria, J. (2012). Product design by application of Taguchi's robust
engineering using computer simulation, International Journal of Computer
Integrated Manufacturing, 25(9), 761-773.
15. Gijo, E.V. and Scaria, J. (2013a). Application of statistical techniques for
improving yield of a manufacturing process, International Journal of Business
Excellence, 6(3), 361-375.
16. Gijo, E.V. and Scaria, J. (2013b). Simultaneous implementation of Six Sigma
methodology with Beta correction technique in automotive supplier process,
International Journal of Advanced Manufacturing Technology, (Under revision).
17. Gijo, E.V., Scaria, J. and Antony, J. (2011). Application of Six Sigma
methodology to reduce defects of a grinding process, Quality and Reliability
Engineering International, 27(8), 1221-1234.
Introduction and Summary of Thesis
17
18. Pradhan, B. and Gijo, E.V. (2013). Parameter estimation of lognormal distribution
under progressive type-I interval censoring, Journal of Statistical Theory and
Practice, (Submitted).
19. Saravanan, S., Meera, M. and Prakash, S. and Gijo, E.V. (2012). Efficiency
improvement on the multicrystalline silicon wafer through Six Sigma methodology,
International Journal of Sustainable Energy, 31(3), 143-153.
1.5.2 Presentations in conferences/ workshops
1. Delivered Invited talk on “National Workshop on Recent Developments in
Statistics with Special Emphasis on Computational Statistics” organized by
University of Kerala, Trivandrum during March 1 – 7, 2013.
2. Presented a paper titled ‘Application of Seasonal ARIMA model in demand
forecasting’ at the ‘IISA 2013 Conference’ held at Chennai during January 2 -5,
2013.
3. Presented a paper titled ‘Quality improvement in manufacturing process: an
application of statistical techniques.’ at the ‘National Conference on Statistics for
Twenty First Century - 2012’ Organized by University of Kerala, Trivandrum,
during December 10 - 12, 2012.
4. Presented a paper titled ‘Quality improvement of automotive supplier process:
application of Six Sigma methodology’ at the ‘2011 Joint Statistical Meeting’ held
at Miami, Florida, US, during 30 July - 04 August, 2011.
5. Delivered talks on ‘Three-day Lecture Workshop on Statistical Applications in
Industry, Business, Agriculture and Ecology’ jointly sponsored by Indian Academy
of Sciences - Bangalore, Indian National Science Academy - New Delhi and The
Chapter 1
18
National Academy of Sciences India – Allahabad, at St. Thomas College, Pala,
Kottayam, Kerala, during March 26 – 28, 2011.
6. Presented a paper titled ‘Six Sigma Methodology in manufacturing process - an
application’ at the ‘National Seminar on Stochastic Modelling and Analysis’
organized by Cochin University of Science and Technology, during March 24 – 25,
2011.
7. Presented a paper titled ‘Improving the performance of CNC machine using
reliability models’ at the ‘Annual Conference of Kerala Statistical Association’ at
University of Kerala, during March 17 – 19, 2011.
8. Delivered a talk on UGC sponsored workshop on ‘Applied Statistical Methods in
Quality Control’ organized by Nirmala College, Muvattupuzha, Kerala on March 3,
2011.
9. Presented a paper titled ‘Process capability improvement of a manufacturing
process through design of experiments’ at ‘International Congress on Productivity,
Quality, Reliability, Optimization and Modelling’ organized by Indian Statistical
Institute, Delhi, during February 7 - 8, 2011.
10. Presented a paper titled ‘What is happening in Six Sigma implementation? An
experience in Indian industries’ at ‘13th International Conference on Quality’
organized by National Institution for Quality and Reliability, Bangalore, during
January 6 – 7, 2011.
11. Presented a paper titled ‘Product design by application of Taguchi’s robust
engineering’ at the ‘International conference on Mathematical Sciences 2011’ at St.
Thomas College Pala, Kottayam, Kerala, during January 3 – 5, 2011.
Introduction and Summary of Thesis
19
12. Presented a paper titled ‘Comparison of univariate and multivariate models in
forecasting: an application’ at the ‘Annual Conference of Kerala Statistical
Association’ at Nirmala College, Muvattupuzha, during February 25 – 27, 2010.
References
1. Adams, C., Gupta, P. And Wilson, C. (2003) Six Sigma Deployment, Butterworth-
Heinemann, Burlington, Massachusetts.
2. Aggarwala, R. (2001). Progressively interval censoring: Some mathematical results
with application to inference, Communications in Statistics-Theory and Methods 30(8-
9), 1921-1935.
3. Andersson, P. (1997). Robustness of technical systems in relation to quality, reliability
and associated concepts, Journal of Engineering Design, 8(3), 277-288.
4. Balakrishnan, N. and Aggarwala, R. (2000). Progressive Censoring: Theory, Methods
and Applications, Birkhauser, Boston.
5. Benton, W. C. (1991). Statistical process control and the Taguchi method: A
comparative evaluation, International Journal of Production Research, 29(9), 1761-
1770.
6. Bisgaard, S. and Freiesleben, J. (2004). Six Sigma and the bottom line, Quality
Progress, 37(9), 57-62.
7. Borkowski, J. J. and Lucas, J. M. (1997). Designs of mixed resolution for process
robustness studies, Technometrics, 39(1), 63-70.
8. Bowerman, B. L. and O’Connell, R. T. (1993). Forecasting and time series: An applied
approach, 3rd edn., Duxbury Press, California.
Chapter 1
20
9. Box. G. E. P. and Bisgaard, S. (1988). Statistical tools for improving designs,
Mechanical Engineering, 110, 32-40.
10. Box, G. E. P., Bisgaard, S. and Fung, C. (1988). An explanation and critique of
Taguchi’s contributions to quality engineering, Quality and Reliability Engineering
International, 4(2), 123-131.
11. Box, G. E. P. and Jenkins, G. M. (1970). Time series analysis, forecasting and control,
Holden-Day, San Francisco.
12. Box, G. E. P., Jenkins, G. M. and Reinsell, G. C. (2008). Time series analysis,
forecasting and control, 4th edn., John Wiley, New Jersey.
13. Box, G. E. P. and Jones, S. (1992). Split-plot designs for robust experimentation,
Journal of Applied Statistics, 19(1), 3-26.
14. Breyfogle III F.W. (2003). Implementing Six Sigma: smarter solutions using statistical
methods, John Wiley, New York.
15. Bunce, M.M., Wang, L. and Bidanda, B. (2008). Leveraging Six Sigma with industrial
engineering tools in crateless retort production, International Journal of Production
Research, 46(23), 6701-6719.
16. Chan, L. K. and Xiao, P. H. (1995). Combined robust design, Quality Engineering,
8(1), 47-56.
17. Chen, D. G., Lio, Y. L. (2010). Parameter estimations for generalized exponential
distribution under progressive type-I interval censoring, Computational Statistics and
Data Analysis, 54(6), 1581-1591.
18. Chen, J.C., Li, Y., and Shady, B.D. (2010). From value stream mapping toward a
lean/sigma continuous improvement process: an industrial case study, International
Journal of Production Research, 48 (4), 1069-1086.
Introduction and Summary of Thesis
21
19. de Gooijer, J. and Hyndman, R. J. (2006). 25 years of time series forecasting,
International Journal of Forecasting, 22(3), 443-473.
20. De Mast, J. (2007). Integrating the many facets of Six Sigma, Quality Engineering,
19(4), 353–361.
21. El-Haik, M. And Roy, D.M. (2005). Service Design for Six Sigma: A road map for
excellence, John Wiley, New Jersey.
22. Ellis, K. (2001). Mastering Six Sigma, Training, 28(12), 30-35.
23. Engel, J. and Huele, A. F. (1996). A generalized linear modeling approach to robust
design, Technometrics, 38(4), 365-373.
24. Ferng, J. and Price, A.D.F. (2005). An exploration of the synergies between Six Sigma,
total quality management, lean construction and sustainable construction, International
Journal of Six Sigma and Competitive Advantage, 1(2), 167-187.
25. Firka, D. (2010). Six Sigma: an evolutionary analysis through case studies, The TQM
Journal, 22(4), 423-434.
26. Ford, R. B. (1996). Process for the conceptual design of robust mechanical systems -
going beyond parameter design to achieve world-class quality, Stanford University,
Palo Alto.
27. Foster Jr., S.T. (2007). Does Six Sigma improve performance?, Quality Management
Journal, 14(4), 7-20.
28. Goh, T. N. (1993). Taguchi methods: some technical, cultural and pedagogical
perspectives, Quality and Reliability Engineering International, 9(3), 185-202.
29. Gowen III, C.R., Stock, G.N. and Mcfadden, K.L. (2008). Simultaneous
implementation of Six Sigma and knowledge management in hospitals, International
Journal of Production Research, 46(23), 6781-6795.
Chapter 1
22
30. Grize, Y. L. (1995). A review of robust design approaches, Journal of Chemometrics,
9(4), 239-262.
31. Gutiérrez Gutiérrez, L.J., Bustinza, O.F. and Molina, V.B. (2012) Six Sigma,
absorptive capacity and organisational learning orientation. International Journal of
Production Research, 50(3), 661-675.
32. Hahn, G.J. (2005). Six Sigma: 20 key lessons learned, Quality and Reliability
Engineering International, 21(3), 225-233.
33. Halliday, S. (2001). So what exactly is Six Sigma? Works Management, 15(1), 15.
34. Harry, M.J. (1997). The Vision of Six Sigma, 5th edn., Tri Star, Phoenix, Arizona.
35. Harry, M. and Schroeder, R. (2000). Six Sigma: the breakthrough management strategy
revolutionizing the world’s top corporations, Doubleday, New York.
36. Huang, R-S, Wu, S-J. (2008). Reliability sampling plans under progressive type-I
interval censoring using cost functions, IEEE Transactions on Reliability, 57(3), 445-
451.
37. Hunter, J. S. (1985). Statistical design applied to product design, Journal of Quality
Technology, 17(4), 210-221.
38. Hossein, A., Steiner, S. H. and MacKay, R. J. (2010). Reducing variation in an existing
process with robust parameter design, Quality Engineering, 22(1), 30 – 45.
39. Hwang, Y.D. (2006). The practices of integrating manufacturing executing systems and
Six Sigma methodology, International Journal of Advanced Manufacturing
Technology, 30(7-8), 761-768.
40. Imai, M. (1986). Kaizen: The Key to Japan’s competitive success, McGraw-Hill, New
York.
Introduction and Summary of Thesis
23
41. Ishikawa, K. and Lu, D.J. (1985). What is total quality control? The Japanese Way,
Prentice Hall, Englewood Cliffs, NJ.
42. Kackar, R.N. (1985). Off-line quality control, parameter design, and the Taguchi
method (with discussion), Journal of Quality Technology, 17(4), 176-188.
43. Karthi, S., Devadasan, S.R. and Murugesh, R. (2011). Integration of Lean Six-Sigma
with ISO 9001:2008 standard, International Journal of Lean Six Sigma, 2(4), 309-33.
44. Keller, P.A. (2001). Six Sigma Deployment, Quality Publishing House, Arizona.
45. Kumar, M., Antony, J., Singh, R. K., Tiwari, M. K. and Perry, D. (2006).
Implementing the Lean Sigma framework in an Indian SME: a case study, Production
Planning & Control: The Management of Operations, 17(4), 407-423.
46. Lazarus, I.R. and Butler, K. (2001). The promise of Six Sigma (Part 1), Managed
Healthcare Executive, 11(9), 22-26.
47. Lee, Y. and Nelder, J. A. (2003). Robust design via generalized linear models, Journal
of Quality Technology, 35(1), 2-12
48. Le´on, R. V, Shoemaker, A. C. and Kacker, R. N. (1987). Performance measures
independent of adjustment, Technometrics, 29(3), 253-285.
49. Lin, C-T, Wu, S.J.S. and Balakrishnan, N. (2009). Planning life tests with
progressively Type-I interval censored data from the lognormal distribution, Journal of
Statistical Planning and Inference, 139(1), 54-61.
50. Lucas, J.M. (1994). How to achieve a robust process using response surface
methodology, Journal of Quality Technology, 26(4), 248-260.
51. Mahesh, M., Wong, Y.S., Fuh, J.Y.H. and Loh, H.T. (2006). A Six Sigma approach for
benchmarking of RP&M processes, International Journal of Advanced Manufacturing
Technology, 31(3-4), 374-387.
Chapter 1
24
52. Montgomery , D. C., Jennings, C. L., and Kulahci, M. (2008). Introduction to time
series analysis and forecasting, John Wiley, New York.
53. Montgomery, D.C. and Woodall, W.H. (2008). An overview of Six Sigma.
International Statistical Review, 76(3), 329–346.
54. Myers, R. M., Brenneman, W. A. and Myers, R. H. (2005). A dual-response approach
to robust parameter design for a generalized linear model, Journal of Quality
Technology, 37(2), 130-138.
55. Myers, R. H., Khuri, A. I. and Vining, G. G. (1992). Response surface alternatives to
the Taguchi robust parameter design approach, The American Statistician, 46(2), 131-
139.
56. Myers, R. H. and Montgomery, D. C. (2002). Response surface Methodology - process
and product optimization using designed experiments, John Wiley, New York
57. Myers, R. H., Montgomery, D. C., Vining, G. G, Borror, C. M. and Kowalski, S. M.
(2004). Response surface methodology: A retrospective and literature survey, Journal
of Quality Technology, 36(1), 53-77.
58. Nair, V.N. (1992). Taguchi’s parameter design: A panel discussion, Technometrics,
34(2), 127-161.
59. Nelson, W. (1982). Applied life data analysis, John Wiley, New York.
60. Ng, H. and Wang, Z. (2009). Statistical estimation for the parameters of Weibull
distribution based on progressively type-I interval censored sample, Journal of
Statistical Computation and Simulation, 79(2), 145-159.
61. Phadke, M.S. (1989). Quality engineering using robust design, Prentice Hall,
Englewood Cliffs, New Jersey.
Introduction and Summary of Thesis
25
62. Pande, P., Neuman, R. and Cavanagh, R. (2000). The Six Sigma way: how GE,
Motorola and other top companies are honing their performance, McGraw-Hill, New
York.
63. Pande, P., Neuman, R. and Cavanagh, R. (2003). The Six Sigma way team field book:
an implementation guide for process improvement teams, Tata McGraw-Hill, New
Delhi.
64. Park, S.H. (1996). Robust Design and analysis for quality engineering, Chapman &
Hall, London.
65. Park, S.H. (2002). Six Sigma for productivity improvement: Korean business
corporations, Productivity Journal, 43, 173-183.
66. Park, G., Lee, T., Lee, K. and Hwang, K. (2006). Robust design: an overview. AIAA
Journal, 44(1), 181–191.
67. Pignatiello, J.J. and Ramberg, J.S. (1991). Top ten triumphs and tragedies of Genichi
Taguchi, Quality Engineering, 4(2), 211-225.
68. Rahmqvist, M. and Bara, A. (2010). Patient characteristics and quality dimensions
related to patient satisfaction, International Journal for Quality in Health Care, 22(2),
86-92.
69. Robinson, T. J., Brenneman, W. A. and Myers, R. M. (2006a). Process optimization via
robust parameter design when categorical noise factors are present, Quality and
Reliability Engineering International, 22(6), 307-320.
70. Robinson, T. J, Wulff, S. S., Montgomery, D.C., Khuri, A. I. (2006b). Robust
parameter design using generalized linear mixed models, Journal of Quality
Technology, 38(1), 65-75.
Chapter 1
26
71. Ross, P.J. (1996). Taguchi Techniques for quality engineering, McGraw-Hill, New
York.
72. Roy, R. (1990). A Primer on the Taguchi method, Society of Manufacturing Engineers,
Dearborn, MI.
73. Scibilia, B., Kobi, A., Chassagnon, R. and Barreau, A. (2001). Robust design: a simple
alternative to Taguchi’s parameter design approach, Quality Engineering, 13(4), 541-
548.
74. Shah, R., Chandrasekaran, A. and Linderman, K. (2008). In pursuit of implementation
patterns: the context of Lean and Six Sigma, International Journal of Production
Research, 46(23), 6679-6699.
75. Shainin, D. and Shainin, P. (1988). Better than Taguchi orthogonal tables, Quality and
Reliability Engineering International, 4(2), 143-149.
76. Smith, B. (2003). Lean and Six Sigma - a one-two punch, Quality Progress, 22(4), 37-
41.
77. Smith, J. and Clarkson, P. J. (2005). A method for assessing the robustness of
mechanical designs, Journal of Engineering Design, 16(5), 493-509.
78. Shoemaker, A. C., Tsui, K. L. and Wu, J. (1991). Economical experimentation
methods for robust design, Technometrics, 33(4), 415-427.
79. Snee, R.D. (2005). Leading business improvement: A new role for statisticians and
quality professionals, Quality and Reliability Engineering International, 21(3), 235-
242.
80. Snee, R.D. and Hoerl, R.W. (2003). Leading Six Sigma: a step by step guide based on
experience at GE and other Six Sigma companies, Prentice-Hall, New Jersey.
Introduction and Summary of Thesis
27
81. Stekler, H. O. (2007). The future of macroeconomic forecasting: understanding the
forecasting process, International Journal of Forecasting, 23(2), 237-248.
82. Taghizadegan, S. (2006). Essentials of Lean Six Sigma, Elsevier, New Delhi.
83. Taguchi, G. (1986). Introduction to Quality Engineering - designing quality into
products and processes, Asian Productivity Organization, Tokyo
84. Taguchi, G. (1988). System of experimental design, Volume 1 and 2, UNIPUB and
American Supplier Institute, New York.
85. Taguchi, G., Chowdhury, S. and Taguchi, S. (2000). Robust Engineering - learn how to
boost quality while reducing costs and time to market, McGraw-Hill, New York.
86. Taguchi, G. and Wu, Y. (1979). Introduction to off-line quality control, Central Japan
Quality Control Association, Japan.
87. Treichler, D.H. (2005). The Six Sigma path to leadership, Pearson Education, Indian
Branch, New Delhi.
88. Tribus, M. and Szonyi, G. (1989). An alternative view of the Taguchi approach,
Quality Progress, 22(5), 46-52
89. Vining, G. G. and Myers, R. H. (1990). Combining Taguchi and response surface
philosophies - a dual response approach, Journal of Quality Technology, 22(1), 38-45.
90. Walters, L. (2005). Six Sigma: is it really different? Quality and Reliability
Engineering International, 21(3), 221-224.
91. Weckman, G.R., Lakshminarayanan, S., Marvel, J. H. and Snow, A. (2008). An
integrated stock market forecasting model using neural networks, International Journal
of Business Forecasting and Marketing Intelligence, 1(1), 30-49.