Article 18_01

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Journal of Engineering Research and Studies E-ISSN 0976-7916 JERS/Vol.I/ Issue II/Oct.-Dec.,2010/177-194 Research Article USE OF SHAININ TOOLS FOR SIMPLIFYING SIX SIGMA IMPLEMENTATION IN QMS/ISO CERTIFIED ENVIRONMENT– AN INDIAN SME CASE STUDY Anand K. Bewoor*, Maruti S. Pawar Address for Correspondence * 1 Mechanical Engineering Dept.,Vishwakarama Institute of Information Tech.,Kondhwa (Bk), Pune 411048, Maharashtra, India 2 Professor and Vice-Principal, B. M. I. T., Solapur University, Solapur Maharashtra, India. E-mail: [email protected], [email protected] ABSTRACT Six sigma for small- and medium-sized enterprises (SMEs) is an emerging topic among many academics and Six Sigma practitioners over the last two to three years. Very few studies have been reported about the successful applications of Six Sigma in SMEs. Main objective of this paper is to examine the extent of usefulness of a simpler but not very frequently used methodology known as the Shainin methodology for simplifying the implementing Six Sigma. To confirm whether Six Sigma implementation is simplified, this paper highlights the comparison of three DOE approaches viz. Classical, Taguchi and Shainin methodology. A case study based research work done in ISO certified Indian SME, concludes that, Six Sigma implementation process can be simplified by using Shainin tools and proper use company’s ISO/QMS. KEYWORDS Six Sigma, Shainin Tools, QMS, Indian SMEs. 1. INTRODUCTION In recent past, academicians, practitioners and organizational researchers have recognized that the Quality Management System (QMS) process and the Six-Sigma process are disciplines that have a powerful potential to affect an organization’s ability to compete within an increasingly global and dynamic marketplace (Falshaw et al., 2006). QMS certification (such as ISO 9000, TS 16949) demonstrates the capability of an industry to control the processes that determine the acceptability of the product or service being produced & sold. These, traditional QMS are having some limitations like methodological assistance etc. (Bewoor and Pawar, 2008). But new QM methods continue to grow (Xingxing Zu et. al., 2008) for example, Six Sigma, which is ‘‘an organized and systematic method for strategic process improvement and new product and service development. Six Sigma relies on statistical methods and the scientific method to make dramatic reductions in customer defined defect rates’’ (Linderman et al., 2003). Since its initiation at Motorola in the 1980s, many companies including GE, Honeywell, Sony, Caterpillar, Johnson Controls etc. have adopted Six Sigma and obtained substantial benefits (Pande et al., 2000). Spectacular development of an organizational performance due to Six Sigma implementation many companies are reported in the published literature. Antony and Banuelas (2002) presented the key ingredients for the effective introduction and implementation of Six- Sigma in manufacturing and services organizations as: Management commit- ment and involvement, Understanding of Six Sigma methodology, tools, and techniques, Linking Six Sigma to business

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  • Journal of Engineering Research and Studies E-ISSN 0976-7916

    JERS/Vol.I/ Issue II/Oct.-Dec.,2010/177-194

    Research Article

    USE OF SHAININ TOOLS FOR SIMPLIFYING SIX

    SIGMA IMPLEMENTATION IN QMS/ISO CERTIFIED

    ENVIRONMENT AN INDIAN SME CASE STUDY Anand K. Bewoor*, Maruti S. Pawar

    Address for Correspondence

    *1Mechanical Engineering Dept.,Vishwakarama Institute of Information Tech.,Kondhwa

    (Bk), Pune 411048, Maharashtra, India 2Professor and Vice-Principal, B. M. I. T., Solapur University, Solapur Maharashtra, India.

    E-mail: [email protected], [email protected]

    ABSTRACT Six sigma for small- and medium-sized enterprises (SMEs) is an emerging topic among many

    academics and Six Sigma practitioners over the last two to three years. Very few studies have been

    reported about the successful applications of Six Sigma in SMEs. Main objective of this paper is to

    examine the extent of usefulness of a simpler but not very frequently used methodology known as the

    Shainin methodology for simplifying the implementing Six Sigma. To confirm whether Six Sigma

    implementation is simplified, this paper highlights the comparison of three DOE approaches viz.

    Classical, Taguchi and Shainin methodology.

    A case study based research work done in ISO certified Indian SME, concludes that, Six Sigma

    implementation process can be simplified by using Shainin tools and proper use companys ISO/QMS.

    KEYWORDS Six Sigma, Shainin Tools, QMS, Indian SMEs.

    1. INTRODUCTION

    In recent past, academicians, practitioners

    and organizational researchers have

    recognized that the Quality Management

    System (QMS) process and the Six-Sigma

    process are disciplines that have a

    powerful potential to affect an

    organizations ability to compete within

    an increasingly global and dynamic

    marketplace (Falshaw et al., 2006). QMS

    certification (such as ISO 9000, TS

    16949) demonstrates the capability of an

    industry to control the processes that

    determine the acceptability of the product

    or service being produced & sold. These,

    traditional QMS are having some

    limitations like methodological assistance

    etc. (Bewoor and Pawar, 2008). But new

    QM methods continue to grow (Xingxing

    Zu et. al., 2008) for example, Six Sigma,

    which is an organized and systematic

    method for strategic process improvement

    and new product and service development.

    Six Sigma relies on statistical methods and

    the scientific method to make dramatic

    reductions in customer defined defect

    rates (Linderman et al., 2003). Since its

    initiation at Motorola in the 1980s, many

    companies including GE, Honeywell,

    Sony, Caterpillar, Johnson Controls etc.

    have adopted Six Sigma and obtained

    substantial benefits (Pande et al., 2000).

    Spectacular development of an

    organizational performance due to Six

    Sigma implementation many companies

    are reported in the published literature.

    Antony and Banuelas (2002) presented the

    key ingredients for the effective

    introduction and implementation of Six-

    Sigma in manufacturing and services

    organizations as: Management commit-

    ment and involvement, Understanding of

    Six Sigma methodology, tools, and

    techniques, Linking Six Sigma to business

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    strategy, to customers, to suppliers, project

    selection, reviews and tracking,

    organizational infrastructure, Cultural

    change, Project management skills,

    Training. All these ingredients make the

    Six Sigma process as a complex process

    and very little efforts has been made for

    simplifying the process of Six Sigma

    implementation process by making use of

    existing QMS and by selecting proper

    implementation tools. Some of the

    criticisms of the Six Sigma methodology

    perhaps stems from the fact that it is

    sometimes too statistical and beyond

    comprehension of the people involved in

    implementing it in practice. Eckes (2001)

    is of the opinion that Six Sigma initiatives

    can fail if the organization believes that

    better quality is possible only through the

    use of sophisticated statistical tools. The

    objective of this paper is to examine as to

    how to simplify and demystify the use of

    Shainin tools for Six Sigma

    implementation tools. At present, the

    impacts of QMS and Six Sigma processes

    on an organizations ability to compete

    have been examined independently. Very

    little emphasis has been given by the

    researchers to conceptually examine the

    potential impact of the synergistic effects

    that might be gained from merging various

    quality management principles and those

    of Six-Sigma process. After doing clause-

    wise analysis Bewoor and Pawar, (2008)

    had proposed the Six Sigma+QMS/ISO

    an integrated concept and successfully

    validated its applicability with the help of

    case study based research. This has

    resulted in to more benefit on operational

    level (Bewoor and Pawar, 2009). This

    case based study helped us to understand

    that if we use simple to use tools, we can

    simplify Six Sigma implementation

    process. The observations and experiences

    in the above case study leads to question

    about how to simplify the implementation

    of Six Sigma with or without QMS/ISO

    systems. The main complex part of the

    implementation of Six Sigma is the

    selection and use of tools for solving

    problems. It is observed that, the efforts to

    simplify the implementation of Six Sigma

    are needed in the area of use of tools. One

    of such efforts/studies is presented below.

    2.PRESENT METHODOLOGIES FOR

    SIX SIGMA IMPLEMENTATIONS

    Pyzdek (2003) has classified Six Sigma

    tools into three categories (refer table 1),

    (i) Basic Six Sigma methods (are further

    categorized as problem solving tools, 7M

    tools, and knowledge discovery tools). (ii)

    Intermediate Six Sigma methods include a

    host of enumerative and analytical

    statistical tools like Distributions,

    Statistical inference, Basic control charts,

    exponentially weighted moving average

    (EWMA) charts etc.). (iii) Advanced Six

    Sigma methods are Design of experiments

    (DOE) Regression and correlation analysis

    Process capability analysis etc. At the

    heart of the Six Sigma approach is the

    application of DOE techniques. These

    techniques help to identify key factors and

    to subsequently adjust these factors in

    order to achieve sustainable performance

    improvements.

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    Table 1 : Basic Six Sigma Tools

    Problem Solving Tools 7M Tools Knowledge Discovery

    Tools

    Process mapping Affinity diagrams Run charts

    Flow charts Process decision program charts Descriptive statistics

    Check sheets Matrix diagrams &

    Tree diagrams

    Histograms

    Pareto analysis Interrelationship diagraphs Exploratory data analysis

    Cause-and-effect

    diagrams

    Prioritization matrices

    Scatter plots Activity network diagrams

    (Source: Pyzdek, 2003)

    While the basic and intermediate methods

    are relatively easier to understand and use,

    the advanced methods are perceived to be

    difficult to comprehend and interpret.

    Design of Experiments (DOE) is one such

    tool. The complexity of these DOE

    techniques that are often cited by

    companies as to the reason why they are

    unable to employ Six Sigma. A short

    overview of the DOE techniques is

    presented next.

    2.1 Experimental Design using

    Classical and Taguchi Approach

    A classical DOE approach would have

    meant application of factorial designs

    requiring much more time and effort, and

    above all, it would have required changes

    in machine settings. Classical DOE

    requires large data collection to conduct

    the analysis. Six Sigma process

    improvements consist of analyzing

    relationships between an output variable

    (Y) explained wholly or partly by process

    variables (Xs) that affect the output. A key

    step in Six Sigma projects is the

    identification of the root cause of the

    problem out of the potential Xs.

    Experimental design is one of the tried

    and tested statistical techniques long used

    by industrial engineers to identify the key

    variables affecting output. Through

    designed experiments, changes are

    deliberately introduced into the process to

    better understand which of the Xs are

    affecting the output variable.

    There are two well-known approaches

    to experimental design. The first approach

    is the classical design of experiments

    credited to Sir Ronald Fisher who initially

    experimented in the field of agriculture.

    However, this method is now widely used

    in many fields. The second approach is the

    Taguchi approach pioneered by Dr

    Genichi Taguchi of Japan who adopted the

    classical approach to reintroduce the

    concept of orthogonal arrays used for

    designing experiments in different fields

    (Rao, et al.). The commonly used classical

    Design of Experiment (DOE) tools are the

    family of factorial experiments consisting

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    of full factorial designs and fractional

    factorial designs. A full factorial allows us

    to test all possible combinations of factors

    affecting output in order to identify which

    ones are more dominant. A fractional

    factorial tests just a fraction of the

    possible combinations. Though a very

    popular tool, many engineers and quality

    practitioners find design of experiments

    difficult primarily because of the

    complexity of having to create the

    conditions for conducting the experiments

    in an industrial environment where

    interrupting production lines and changing

    machine settings may be sometimes

    difficult and unproductive.

    2.2 Shainin DOE Approach

    An alternative to the Classical and

    Taguchi experimental design is the lesser-

    known but much simpler Shainin DOE

    approach developed and perfected by

    Dorian Shainin (Bhote and Bhote, 2000),

    consultant and advisor to over 750

    companies in America and Europe.

    Shainins philosophy has been, Dont let

    the engineers do the guessing; let the parts

    do the talking. Shainin recognized the

    value of empirical data in solving real-

    world problems. He introduced the

    concept of Red X, the dominant source of

    variation, among the many sources of

    variation of a problem that inevitably

    accounts for nearly all the unwanted

    effect.

    In fact, Shainin (Shainin, 1995; 1993b)

    had classified all causes of chronic quality

    problems into three Xs, viz., the Red X,

    the Pink X- the second most important

    cause(s), and the Pale Pink X the third

    most important cause(s). According to

    him, these three Xs together account for

    over 80 per cent of the variation that is

    allowed within the specification limit and

    when captured, reduced, and controlled,

    these can eliminate this variation. Shainin

    developed techniques (Shainin and

    Shainin, 1990; 1992a; 1992b; 1993a;

    1993b; Shainin, Shainin and Nelson,

    1997) to track down the dominant source

    through a process of elimination (Shainin,

    1993b), called progressive search. These

    techniques, also referred to as the Shainin

    System for quality improvement,

    developed over a period of over 40 years,

    are simple but at the same time powerful

    and easier to interpret and implement in an

    industrial environment. In a way, these

    may be considered as the non-parametric

    equivalent of Taguchis DOE as they do

    not make any restrictive assumptions

    about population parameters. The Shainin

    techniques are primarily known to

    produce breakthrough improvements in

    eliminating chronic quality problems.

    These are highly effective in pinpointing

    towards the root cause and validating it.

    No statistical software was needed to

    analyze the data. In fact, Shainin DOE

    does not even require knowledge of

    difficult statistical tools. Simple operation

    like counts, additions, subtractions, etc.,

    makes calculations relatively easy. In

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    addition, the success of the projects can

    lead to a very positive effect on the morale

    of the employees in terms of convincing

    them that Six Sigma can be implemented

    without complex statistics and big jargons.

    The subject of the Shainin methods is very

    vast and this paper highlights the

    applicability of only a few of the Shainin

    tools. However, there is a lot of scope for

    more research on this methodology

    particularly comparative research of some

    of the Shainin methods like Paired

    Comparison and B Vs C Analysis vis--

    vis the more popular statistical tools like

    factorial designs and non-parametric

    testing. Although these methods are not

    necessarily the best, according to Steiner

    et al. (2008), the guiding principles of the

    Shainin tools are powerful, and at least, in

    combination, unique. Also, these tools are

    best suited for batch to high volume

    production.

    3. FINDINGS FROM VARIOUS

    CASE STUDIES ABOUT DOE

    APPROACHES

    Bhote and Bhote (2000) described these

    tools in their books, but there have been

    many criticisms regarding their claims and

    the tools described. Though, Nelson

    (1991) and Moore (1993) criticized the

    Shainin System as unsubstantiated and

    exaggerated, Steiner, et al (2008), are of

    the opinion that some of the ideas behind

    the Shainin System are genuinely useful.

    Goodman and Wyld (2001) offered a case

    study involving the use of Shainin DOE in

    an industrial operation. Applications of the

    Classical and Taguchi methods in various

    fields have been extensively researched. In

    contrast, the Shainin system has not been

    extensively reviewed, academically, and

    very limited studies have been carried out

    in this area.

    3.1 Studies about comparison of

    DOE approaches

    Bhote (2000) compared Shainin

    techniques with Design of Experiments

    and Taguchi methods, in the context of the

    electronics industry and concluded that the

    Shainin techniques are simpler, less

    costly, and statistically more powerful

    than the other two. Logothetis (1990) also

    evaluated the Shainin techniques in

    relation to the Taguchi methods and

    statistical process control methods.

    Verma, et al (2004) used a slightly

    different approach to compare the

    methods. In their study, three cases of

    Taguchi experiments were picked up from

    the available literature and the Shainin

    method was then re-applied to find out

    whether it had an edge over the other DOE

    techniques. A comparison between

    Taguchi and Shainin techniques in an

    aerospace environment was offered by

    Thomas and Anthony (2005). A few other

    authors who have studied these techniques

    are Ledolter and Swersey (1997), De

    Mast, et al. (2000) and Steiner and

    MacKay (2005). The Classical DOE,

    Taguchi DOE, and Shainin DOE are

    compared with each other in Table 2.

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    Table 2:Comparison of Classical, Taguchi, and Shainin DOE Approaches

    Items for

    compari-

    son

    Classical DOE Taguchi DOE Shainin DOE

    Primary

    tools

    Factorial experiments

    Orthogonal arrays

    a. Component search,

    b. Multi-vari analysis,

    c. Paired comparison,

    d. Product/Process Search or,

    variable search, e. Full

    factorials, f. B vs. C (Better

    vs. Current) analysis, Scatter

    plots.

    Advan-

    tage

    Effective when

    interaction effects are

    not present

    (20 to 200%

    improvements).

    Limited possibilities

    for optimization.

    Effective when

    interaction

    effects are not present

    (20 to 200%

    improvements).

    Limited possibilities for

    optimization.

    Very powerful irrespective of

    the presence or absence of

    interactions. Maximum

    optimization possible.

    Cost/Tim

    e Moderate Moderate Low

    Training 3 to 5 days 3 to 10 days 1 to 2 days

    Complexi

    ty Moderate High

    Low (simple & basic

    mathematical operations)

    Facility &

    Scope

    Requires use of

    statistical software

    e.g., SAS, SPSS, etc.

    Used mainly in

    production.

    Requires use of

    statistical software e.g.,

    SAS, SPSS, etc. Used

    mainly in pre-

    production & can be

    used at the design stage

    under certain

    constraints.

    Software not necessary.

    Ease of

    Imple-

    mentation

    Moderate (Requires

    knowledge of

    statistics. Engineers

    find methods

    complex to

    comprehend and

    interpret.)

    Poor

    High (Almost no knowledge

    of statistics required. Easy to

    understand at all levels

    including shop floor workers,

    engineers, and suppliers, thus

    creating an overall positive

    impact.

    (Bothe & Bothe, 2000)

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    An examination of the three approaches

    clearly indicates that the Shainin tools

    have an edge over the other two

    approaches in terms of cost, time, training,

    complexity, scope, and ease of

    implementation. The following work

    highlights the tools and techniques that

    were used by Indian SME, a

    manufacturing unit of Gange Industries

    (GI) in their development of the six sigma

    programme

    4. CASE STUDY

    This case-study was successfully

    completed in the welding unit of GI,

    which is a SME was established in 1985,

    located at Bhosari M.I.D.C., Pune,

    Maharashtra State in India. GI has grown

    to become a one of the major player in

    processing/manufacturing of automobile

    sheet-metal parts. GI is ISO 9001 and TS

    16949 certified and has implemented

    company wide QM, Kaizen and TPM

    initiatives to good effect.

    The company from their past experience

    found that the QM process and its

    associated systems were too slow in

    identifying and responding to problems

    primarily, since they were developed to

    obtain long-term strategic direction and

    focus. Therefore, company officials had

    accepted and initiated move towards use

    of Shainin tools for implementation of

    Six Sigma + QMS integrated approach

    for increase the process quality,

    productivity intern reducing process cost.

    Until the introduction of the integrated

    strategy, the company attended to quality

    problems in an often ad-hoc and

    unstructured manner.

    The following section followed how

    the company followed the proposed

    methodology in an attempt to provide a

    structured approach to solving critical to

    quality (CTQ) problems within the

    company and to achieve enhanced process

    quality, productivity, customer satisfaction

    and internal benefits through a case study

    of one particular project undertaken.

    Six Sigma DMAIC Process

    The six sigma process concentrates on a

    simple five phase methodology called

    DMAIC (Define, Measure, Analyze,

    Improve, Control). The company followed

    this approach and each stage is explained

    in detail in the following section of the

    paper.

    Define Phase: The data available

    (collected through QMS) related to type,

    frequency and amount of rework done at

    GI is analyzed. Our team (which includes

    companys management representative,

    managers, engineers and author) at GI

    confirmed that, parts named Assy-sub

    structure with floor (613 LP RUSSIA)

    (XXX 6100 0182), which fits into

    assembly frame of light commercial

    vehicle after welding on Welding M/C

    ST-CO2-17 machine was under rejection

    because of defective welding (non

    uniform welding, weld penetration, dry

    welding, weld under cut and spatter etc.),

    which resulted in to annual Cost of Poor

    Quality (COPQ) about INR 2Lakh/-.

    Process stages, where the problem

    detected are in-process inspection and

    final inspection. This project was

    undertaken to achieve certain objectives

    viz. productivity improvements in terms of

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    reduction/elimination of reworks and

    reducing process cost [tangible], customer

    satisfaction, and increase in confidence on

    shop floor [intangible]. Hence,

    repeatability and reproducibility study was

    required for validating the measurement

    system. Process Mapping is carried out

    (refer figure 1),

    Measure and Analyze Phase: A

    brainstorming exercise was carried out by

    a multi-disciplinary team of engineers

    within the company. The team identified

    the factors that could influence the product

    quality. A cause-and-effect diagram was

    developed (refer figure 2) to identify the

    key sources of variation during the

    welding process. Two potential

    Suspectable Sources of Variations (SSVs)

    were finally listed as: Sheet material

    thickness, Welding Process itself.

    Figure 2: Cause-and-Effect Diagram

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    Without taking educated guesses as to the

    factors of real importance, authors have

    suggested to adopt the Shainin

    Techniques. The Shainins Techniques

    been employed to identify whether the

    primary cause of shabby/defective

    welding lay within the process itself or

    within the components used. This allowed

    for a first stage filter to be employed that

    cut down the factors to a manageable

    number. Key stages, in which Shainin

    tools were applied, are explained below.

    Initial tool selected for measuring and

    analyzing the response was Product

    Process Search, as of variations in the

    identified suspectable sources of

    variations (SSV) i.e. input material

    parameter (as compared with their

    standard specification) viz. SSV-1.

    Material Thickness (Specifications 2.0

    mm +/- 0.18), gets changed during

    processing. Data was collected for 100

    samples.

    Observation 1 It has been observed that,

    minimum and maximum value of sheet

    metal (raw material) thickness as an

    important input to production process

    belongs to same category of response.

    Therefore, as per Product Process Search

    method the end-count is zero. Hence, it

    has been concluded that, SSV-1: Input

    material parameter (i.e. Thickness) is not

    creating problem. Next another

    brainstorming session has concluded for

    characterization of CO2-Welding process

    as process itself is yielding in to

    variations, which is required to be

    analysed. Hence, relation can be written

    as; BigY (Response i.e. Defective welding)

    = f [X (Sources of variations i.e. CO2

    Welding process)]. Therefore, new SSVs

    are now related to CO2-Welding process

    are listed viz. Voltage, Current, Gas Flow

    and Wire Feed Rate. To check whether

    any relationship exists within the

    identified parameters or not; data related

    to all these parameters are collected (refer

    table 3), regression analysis is carried out

    and Graphs are plotted. Graph of Wire

    Feed Rate vs Current clearly shows the

    positive relationship (refer figure no. 3).

    Hence, new SSVs identified parameters

    related to CO2-Welding process are now

    limited to: Voltage, Wire Feed Rate and

    Gas Flow.

    As the identified parameters were design

    parameters of process and number of

    parameters are equal to 3 hence, it has

    been decided that, process characterization

    analysis i.e. Full Factorial Analysis tool is

    to be used. All stages of full factorial

    method are explained as follows,

    Stage 0: As the response is attribute in

    nature, consider current setting as the

    setting and identify + setting on the basis

    of experience on domain expert for each

    parameters (refer table 4).

    Stage 1: To find out whether the

    parameters and the levels identified in

    stage 0 are correct or not. Then, we have

    to produced 3 batches in setting and 3

    batches in + setting. Calculate D/d ratio,

    if D/d ratio is >=1.25 and

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    tabulated in table 5. D/d ratio is 0.4, which

    indicates that, the levels identified in stage

    0 are not correct. Hence, new parameters

    levels are identified by considering earlier

    + ve setting as new - setting and new

    + ve settings for all parameters are

    identified and set (refer table 6). Again

    new trials are conducted and the results

    are tabulated in table 7. D/d ratio is 10,

    which indicates that the levels identified in

    2nd settings are acceptable for further

    consideration.

    Stage 2: Construct factorial table and

    collect the data for each combination in

    the factorial table and quantify the

    contributions of the interactions.

    Table 8 shows factorial design and plan

    of experimentation. Accordingly

    experiments were performed, which

    resulted in to following important

    conclusions.

    Parameter- A: As if we change from +

    level to - level then response increases by

    2.5 points.

    Parameter- B: As if we change from +

    level to - level then response decreases by

    1.5 points.

    Parameter- C: As if we change from +

    level to - level then response decreases by

    5 points.

    Stage 3: Make a simple mathematical

    equation based on the contribution of

    significant parameters and arrive at the

    optimal setting.

    Y= 84.875 3.125 A + 14.162B + 4.875C

    +2.625 AB 4.375 BC 7.125 CA +

    7.625ABC

    As response Y considered is

    shabby/defective welding hence, our

    objective is lower the better. Using above

    equation, offline iterations are done.

    While doing iterations +ve settings are

    refereed as 1, - settings are referred as

    -1. Values some of the offline iterations

    and its calculated responses are tabulated

    in table 9. Then, experiments are carried

    out using the levels of the parameters for

    which responses are zero or less than zero

    and physical outputs are analyzed.

    Response for setting in case of experiment

    no. 9 (shown in same table) resulted in to

    proper welding (considered as an optimum

    output).

    Improvement Phase: Conclusions of

    earlier phase (identified optimum levels of

    the parameters as shown in table 10) are

    used as an input to this phase. Once

    optimum settings are set then, it is

    necessary to validate it. This was done, by

    using the Shainin B vs. C analysis, which

    is a confirmation tool to verify whether

    the actions taken have actually improved

    the process (Bhote and Bhote, 2000). In

    this case, 6B vs. 6C, i.e., 6 batches (10

    units per batch) with modification and 6

    (10 units per batch) without modification

    (B with modification and C without

    modification) was analyzed to validate the

    improvement action, i.e., the modification

    of CO2 machine operating parameters

    (table 11).

    The data in table 12 exhibited the

    responses with B and C conditions. As per

    rule of this technique, the final analysis is

    done based on the end-count scheme. In

    this case, end count is 8 (greater than 6),

    which confirms that identified root causes

    are correct.

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    Further, the result clearly validates the

    improvement against the criteria

    mentioned in table 13. The data has

    exhibited no overlaps of the responses

    with B condition and C condition. The

    conclusion being that the process has been

    improved by changing the CO2 welding

    machine operational specifications as

    mentioned in table 10. New specifications

    not only helped to improve the quality

    level but also productivity by reducing

    defect/rework rate and optimizing the use

    of resource and time (e.g. Wire Feed Rate

    from 10 Min/min to 6.5 Min/min and Gas

    Flow from15 Lit/min to 14 Lit/min).

    Table 3: Data related to all these interactions among identified parameters

    Sr. No. wire feed voltage current

    1 50 27 40

    2 55 13 90

    3 55 16 100

    4 55 18 80

    5 55 20 100

    6 55 22 110

    7 55 22 110

    7 55 25 100

    9 55 28 90

    10 55 30 90

    11 65 17 100

    12 65 19 100

    13 65 23 100

    14 75 30 160

    15 80 20 150

    16 80 27 140

    17 100 26 190

    Table 4: First Setting of levels of each parameter

    Sr. No. Parameter UOM Existing Setting (- ve ) Modified Setting (+ ve )

    A Wire Feed Rate Min/min 10 7

    B Voltage V 26 20

    C Gas Flow Lit/min 15 8

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    Table 5: First Trial

    Trial - Setting + Setting

    1st Trial 10 50

    2nd Trial 50 50

    3rd Trial 40 60

    Median 40 50

    Range 40 10

    D = Difference Between Two Medians 10

    d = Average of Two Ranges 25

    D/d 0.4

    Table 6: Second Setting of levels of each parameter

    S. N. Parameter UOM Existing Setting ( - ve ) Modified Setting (+ ve )

    A Wire Feed Rate Min/min 7 4

    B Voltage V 20 18

    C Gas Flow Lit/min 8 6

    Table 7: Second Trial

    Trial - Setting + Setting

    1st Trial 50 100

    2nd Trial 50 100

    3rd Trial 60 100

    Median 50 100

    Range 10 0

    D = Difference Between Two Medians 50

    d = Average of Two Ranges 5

    D/d 10

    Table 8:Factorial Table

    Factors (Main Effects) Factor interaction

    A B C AB BC CA ABC Response Median

    7 " - " 20 " - " 8 " - " " + " " + " " + " " - " 50 , 50, 60 52

    4 " + " 20 " - " 8 " - " " - " " + " " - " " + " 70 70

    7 " - " 18 " + " 8 " - " " - " " - " " + " " + " 100 100

    4 " + " 18 " + " 8 " - " " + " " - " " - " " - " 70 98

    7 " - " 20 " - " 6 " + " " + " " - " " - " " + " 100 100

    4 " + " 20 " - " 6 " + " " - " " - " " + " " - " 60 59

    7 " - " 18 " + " 6 " + " " - " " + " " - " " - " 100 100

    Parameters

    Settings

    4 " + " 18 " + " 6 " + " " + " " + " " + " " + " 100, 100,

    100 100

    " - " 88 70.25 80 82.25 89.25 92 77.25

    " + " 81.75 99.5 89.75 87.5 80.5 77.75 92.5

    Sign " - " " + " " + " " + " "-" " - " " + "

    Difference 6.25 29.25 9.75 5.25 8.75 14.25 15.25

    Coeff. 3.125 14.625 4.875 2.625 4.375 7.125 7.625 84.874

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    Table 9:Offline iterations, its calculated and actual responses

    Expt.

    No. Wire Feed Voltage Gas Flow Constant Response Remark

    1 0 0 0 84.875 84.88

    2 -1 -1 -1 84.875 52

    3 1 1 1 84.875 100

    4 -.5 -2 -2 84.875 10.19 Poor adhesion

    5 -0.45 -2 -2.5 84.875 0.0

    6 -0.5 -3 -3 84.875 -52.50 Poor adhesion

    7 -0.6 -5 -5 84.875 -248

    8 -0.6 -9 -7 84.875 -507.20 Poor adhesion

    9 -0.65 -9 -7 84.875 -684 OK 10 -2 -11 -7 84.875 -1652 High Penetration

    Table 10: Existing and Optimum Settings

    Sr.

    No.

    Parameter UOM Existing Setting

    ( -) ve

    Optimum Setting

    (0 - Target )

    A Voltage V 26 28

    B Current A 200 150

    C Wire Feed Rate Min/min 10 6.5 D Gas Flow Lit/min 15 14

    Table 11: B vs. C analysis

    1 Part number selected for validation ASSY substructure with floor

    Better Condition Optimum Settings (Refer table 10 ) 2 Current Condition -

    3 Sample size 6B,6C

    4 Sample type Batches

    5 Response decided for monitoring % Rejection

    6 Lot quantity (for batches) 10

    Table 12:B vs. C Response

    Lot no. Better ( B ) Current ( C )

    1 0 40

    2 0 30

    3 10 10

    4 10 40

    5 0 30

    6 0 40

    Table 13: Criteria for validating improvements and results

    Sr. no. Criteria for validating improvements Results

    1 Part selected for validation Sub structure assembly with floor

    Average of B 3.33 2

    Average of C 31.66

    3 Xb Xc (Amount of Improvement) 28.33

    4 Sigma (B) 4.71

    5

    Is [Xb - Xc] greater than [K x Sigma (b)]

    (Where K is std value = K = 2.96 @ 95%

    Confidence Level )

    Yes [(28.33 > 19.78]

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    The improvements identified were also

    used to set the action plan for other

    varieties of such components for

    horizontal deployment.

    Control Phase:

    The focus of the control phase is to sustain

    the gains of the improvement phase. This

    is usually achieved by documentation and

    standardization of the control measures.

    For controlling the process at Six Sigma

    level, following actions were suggested.

    Appropriate modifications have been

    done in CO2 welding machine operating

    and training manuals.

    Procedure has been developed for

    periodic monitoring of CO2 welding

    machine operational specifications w. r. to

    quality level of output.

    Implemented controls to make sure

    that the actions taken in Phase-III are done

    forever.

    All these modifications have been

    included as a part of Company-QMS

    procedure to ensure the reliability of Six

    Sigma level quality of the process.

    The operational framework developed and

    used in this research-work is described in

    figure 4.

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    It clearly shows the major stages in the

    process integration and implementation. It

    shows initially the sequential nature of the

    stages whereby the Six Sigma phases are

    using appropriate imputes from company

    QMS database to continently execute the

    project. The operational framework also

    shows the stages in sequence whereby the

    six sigma DMAIC phases are using

    accurately Shainin quality tools.

    5. DISCUSSION AND CONCLUSIONS

    The aim of this project is to defeat the

    biggest excuses cited by SMEs as the

    reasons Six Sigma is not feasible, incurs

    high costs and involve complexity of

    implementation. In addition, it helps to

    break down so many of the barriers that

    stand in the way of individuals using

    statistical and/or unfamiliar problem

    solving methods by acting as a step-by-

    step guide. This research work focus on

    use of Shainin tools specifically, as they

    are easy to understand, involves simple

    mathematical calculations (so that bottom-

    line people can also understand it very

    easily) and time required for training is

    also less, which is one of the important

    requirements of SMEs. During this case

    study, during use of Shainin tools, small

    samples of BOB and WOW pieces were

    sufficient to analyse the data as reported

    earlier. A very important factor is that data

    collection was done for the project

    undertaken online without disturbing the

    regular production.

    Thus in short, we can understand that, use

    of Shainin tools for simplifying Six

    Sigma implementation can provides an

    appropriate methodology for SMEs for

    delivering certain objectives set by ISO

    such as: prevention of defects at all stages

    from design through servicing; techniques

    required for establishing, controlling and

    verifying process capability and product

    characterization; investigation of the cause

    of defects relating to product, process and

    quality system; continuous improvement

    of the quality of products/services.

    From the results of case study based

    research work we draw following

    conclusions,

    i. The key phase of the DMAIC

    methodology is the measure and

    analysis phase. The tools and

    techniques used in this phase

    determine the success or failure of

    the project to a large extent. In

    both the projects, the Shainin tools

    have been very effectively used to

    pinpoint the root causes and

    validate the improvement actions.

    ii. No statistical software was needed

    to be used to analyse the data. In

    fact, Shainin DOE does not even

    require knowledge of difficult

    statistical tools. Simple operation

    like counts, additions, subtractions

    etc., makes calculations relatively

    easy. Therefore the training

    required for application of Shainin

    tools is simple and requires less

    time (1-2 days).

    iii. In addition, the success of the

    projects had a very positive effect

    on the morale of the employees in

    terms of convincing them that Six

    Sigma works without complex

    statistics and big jargons.

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    iv. Existing company QMS

    procedures has assisted

    /complimented in all stages of

    implementation of Six Sigma.

    v. Operational framework developed

    and used in this research-work has

    validated for its implementation

    and found to be a useful concept

    for improving quality and

    productivity/performance of SME.

    vi. The project was completed within

    a span of almost three months. For

    the company, the estimated

    savings from this project was

    more than INR 2 lakhs per annum.

    The guiding principles of the Shainin tools

    are powerful, and at least, in combination,

    unique. Therefore, we conclude that,

    applying simplified Shainin tools based

    Six Sigma methodology to the existing

    company QMS process is the best way for

    SMEs to achieve the optimal results in

    quality progress towards TQM in

    customer satisfaction.

    This paper highlights the applicability of

    only a few of the Shainin tools. There is a

    lot of scope for more research on this

    methodology as its most of the

    terminology is trademarked and legally

    protected, limiting academic debate and

    discussion on this system of problem

    solving, which despite many criticisms

    and having been largely overshadowed by

    the classical and Taguchi techniques in the

    past, is now gradually being given its due

    recognition.

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