Document Sample
 International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
 6340(Print), ISSN 0976 – 6359(Online) Volume 3, Issue 2, May-August (2012), © IAEME
ISSN 0976 – 6340 (Print)
ISSN 0976 – 6359 (Online)
Volume 3, Issue 2, May-August (2012), pp. 59-66
Journal Impact Factor (2011): 1.2083 (Calculated by GISI)        ©IAEME


                U. D. Gulhane*, C.A.Nalawade, K.P.Sohani , V.S.Shirodkar
       Department of Mechanical Engineering, Finolex Academy of Management and
                    Technology, Ratnagiri, Maharashtra 415612, India
        *Corresponding author- Asst. Professor, Dept. of Mechanical Engineering,
    Finolex Academy of Management and Technology, P-60/61, MIDC, Mirjole Block,
               RATNAGIRI- (M.S.) 415639, India, Tel.: +91-9226797252,
             Fax: +91-02352228436, E-mail ID:

         In recent years, many methods have been proposed and implemented to improve
 operations performance. A phenomenon cannot be scientifically studied until it is
 defined; therefore, we provide a starting point for future research on Six Sigma. Due to
 globalization and increasing competition, TQM was phased out and a new method Six
 Sigma evolved. Six sigma implementation requires sound knowledge of underlying
 theory.This paper proposes implementation of six sigma model to medium scale tool

 Keywords: Six Sigma, DMAIC, Quality tools

         Intensive competition pressure gave rise to many of management philosophies in
 order to gain an edge over competition. Starting from the 1980s, an attempt was made to
 establish a connection between quality management and other departments like
 marketing, logistics etc. For the past few years, several studies have examined connection
 between quality and performance. Visionary leadership, internal and external
 cooperation, process management, and employee fulfillment are the key constructs of
 quality management. Moreover, they demonstrated that these constructs are drivers of
 customer satisfaction. Similar constructs have been identified in other studies and been

International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
6340(Print), ISSN 0976 – 6359(Online) Volume 3, Issue 2, May-August (2012), © IAEME

shown to positively aspect of product quality and broader measures of manufacturing
        On this journey of companies to excel in quality it is realized that getting quality
products at low cost and better services are essential for customer satisfaction. This
environment gave rise to TQM and Six Sigma. Six Sigma is a smarter way to manage a
business or a department. Six Sigma puts the customer first and uses facts and data to
drive better solutions.Although the tools and techniques inSix Sigma are strikingly
similar to prior approaches to quality management but it provides an organizational
structure not previously seen.what is new in Six Sigma when compared to prior quality
management approaches is more its organizational implementation rather than the
underlying philosophy or the quality tools/techniques employed.[1]
        Despite the immense popularity and the wide-spread adoption of Six Sigma, there
is an increasing concern across industries regarding the failure of Six Sigma programs.
One reason many Six Sigma programs fails is because an implementation model detailing
the sequence of Six Sigma elements/activities is not available.[2]
Six Sigma efforts target three main areas like Improving customer satisfaction, reducing
cycle time and reducing defects. Improvements in these areas usually results in cost
savings to businesses, along with opportunities to retain customers, capture new markets,
and build a reputation for top performing products and services.[3]

        Characteristics of Six Sigma are it is customer focused. It keeps customer’s view
as a reference and designs and implements changes accordingly. It projects produce
major returns on investment. It produces number of minute changes which indirectly or
directly result in cost reduction and hence profit. It changes how management operates.
Six Sigma is much more than improvement projects. Senior executives and leaders
throughout a business are learning the toolsand concepts of Six Sigma: new approaches
to thinking, planning, and executing to achieve results. In a lot of ways, Six Sigma is
about putting into practice the notions of working smarter, not harder. [3]

         Six Sigma hierarchy consists of Black belt a full-time person dedicated to tackling
critical change opportunities and driving them to achieve results. Master Black belt
serves as a coach and mentor or consultant to Black Belts working on a variety of
projects. The Master Black Belt is a real expert in Six Sigma analytical tools, often with a
background in engineering or science or an advanced degree in business. Green Belt is
someone trained in Six Sigma skills, often to the same level as a Black Belt. But the
Green Belt still has a “real” job and serves as either a team member or a part-time Six
Sigma team leader. A Champion is an executive or a key manager who initiates and
supports (sponsors) a Black Belt or a team project. Implementation Leader is either a
seasoned professional in organizational improvement or quality or a respected inside
executive with significant company experience and strong leadership and administrative
abilities. This is a high-stress, high-demand job with short-term goals, long-term visions,
and significant accountability

       Define is first stage in any six sigma project it consist of developing team charter
and process map. This stage gives problem statements, constraints and assumptions, team

International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
6340(Print), ISSN 0976 – 6359(Online) Volume 3, Issue 2, May-August (2012), © IAEME

players and roles, scope and primary plan. Output of this stage is charter of projects
Measure is the second and important step in DMAIC model is measure which deals with
measuring of current sigma ratings, also it defines performance standards. Gathering of
relevant data is crucial for further success of project. It is also important that data
obtained is presented in such a format that areas causing problems can be pinpointed
easily. In Analyze, the DMAIC team delves into the details, enhancesits understanding of
the process and problem, and, if all goes asintended, identifies the root cause of the
problem. One of the principles of good DMAIC problem solving is to consider many
types of causes, so as not to let biases or past experience cloud the team’s judgment.
Some of the common cause categories to be explored are man, machine, material,
method. Improve Assumption busting and other creativity exercises help the team shake
up its thinking and approach idea generation in new ways. The team may also look at
other companies or other groups in their business to see whether they can borrow “best
practices” from elsewhere. Once several potential solutions have been proposed, the
analytical headsets go back on, and several criteria, including costs and likely benefits,
are used to select the most promising and practical solutions. The “final” solution or
series of changes must always be approved by the Champion and often by the entire
leadership team. Trials are carried out to ensure improvements. Control involves
monitoring the improved process continuously to ensure long term sustainability of the
new developments. Documenting the results and accomplishments of all the
improvement activities for future reference is also important.
        Tools used in DMAIC model are very important for team players to understand,
proper choice of tool is essential for success of the project. Tools for generating ideas and
organizing information are Brainstorming, Structure tree (tree diagram),High-level
process map (SIPOC diagram) ,Flowchart (process map),Cause-and-effect (ishikawa)
diagrams .Tools for data gathering are Sampling ,Operational definitions ,Voice of the
customer (VOC) methods ,Check sheets and spreadsheets. Tools for process and data
analysis are Process-flow analysis ,Pareto chart Histogram (frequency plot), Scatter plot
(correlation) diagram .Tools for statistical analysis are Correlation and regression Design
of experiments. Tools for implementation and process management are Project
Management Methods ,Potential Problem Analysis and Failure Mode and Effects


J.K.Files is file producing company. Here various six sigma tools were used to produce
model for implementation.

        The 6 “ RT file is a fast-moving product of JK Files Ltd and constitutes nearly
half of the companies production . It has a separate semi-automated line of production
which is an added advantage as changes required can be implemented easily. It would
have a great impact if the rejection is reduced.
Problem Statement

International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
6340(Print), ISSN 0976 – 6359(Online) Volume 3, Issue 2, May-August (2012), © IAEME

        To decrease the current rejection rate (35000 defects per million opportunities) of
6 “ Regular Taper File to minimum possible rejection rate (less than 10000 defects per
million )
Constraints & Assumptions
        This being a implementation model the feasibility of changes has to be studied
thoroughly with the help of concerned personnel, No defects exist in the delivery of
finished product to the customer, Negligible or no defects occur in pre and post
production processes of the 6 “RT file , Our model will be restricted only to production
process of 6 “ RT.
Various tools such as process flow diagram, Ishikawa, Pareto charts are used to gather
and analyze data. We studied the process flow of that productwhich is essential for
further analysis.
The priorities to be given are as follows :
    1. Up cutting
    2. Grinding
The type of data gathered is of Discrete type .

                    Fig.1 Flow Chart of Production Process of 6”RT

International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
6340(Print), ISSN 0976 – 6359(Online) Volume 3, Issue 2, May-August (2012), © IAEME

        Pitch Variations is the variation distance between point on one teeth of a file to
corresponding point on the successive teeth. Grinding Marks appear on the file due to the
variation of grinding pressure. Some marks are visible immediately after grinding but
certain marks become visible after upcutting .Less/more deep cut occurs due to the
change in pressure of the chisel. Bad edge can occur due to improper handling of the file
while preparing it for grinding. In Level out, the file after grinding may not be plane on
the surface due to improper grinding which results to one of the above rejections.
    The number of each rejection was noted in the sample size of 500 .Above data is
represented below using pareto chart & also the current sigma rating is shown below. We
collect data on 500 files and find that 31 were pitch variation, 16 were grinding marks, 10
were uneven deep cut, 10 were level out and 5 were bad edge. To calculate sigma, we
take the total number of defects counted, divide by the total number of units, and multiply
by the number of defect opportunities:
                        DPMO={(31+16+10+10+5)/(500 x 5)} x 10^6
This gives us 72/2500 i.e 0.0288; we call this defects per opportunity (DPO), we usually
consider 1 million opportunities, so that would be 28,800 defects per million
opportunities (DPMO). Now all you do is look up that DPMO number in a table 1 to find
what sigma it represents. In this case, the production process is performing at about 3.4
                             Table 1 Sigma Equivalence Table

International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
6340(Print), ISSN 0976 – 6359(Online) Volume 3, Issue 2, May-August (2012), © IAEME

    The data obtained clearly suggests that major rejections are of pitch variation and
less/more deep cut Now we used tools such as Ishikawa and pareto analysis to get idea
about the root cause of defects. These defects are organized into man, machine, material,
mother nature depending upon their origin. Given below are two ishikawa diagrams of
prioritized processes in the entire production. After collection of data we first find out the
major defects that are responsible for bigger part of rejection, for that we use most widely
used and one of 7 QC tools i.e. Pareto analysis.

                                   Fig. 2 Pareto Analysis

International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
6340(Print), ISSN 0976 – 6359(Online) Volume 3, Issue 2, May-August (2012), © IAEME

               Fig. 3 Cause and Effect Diagram for Upcutting Process

                Fig. 4 Cause and Effect Diagram For Grinding Process

International Journal of Mechanical Engineering and Technology (IJMET), ISSN 0976 –
6340(Print), ISSN 0976 – 6359(Online) Volume 3, Issue 2, May-August (2012), © IAEME

        With above data at hand we generate number of potential solutions which will
reduce the rejections. The solution to be applied should be verified using design of
experiment tool. Also we have suggested few remedies for grinding and upcutting
        For Grinding the remedies are Precision tanging of the file, Use of gauges after
tang forging, Use of proper jigs and fixtures, Constant monitoring of pressure applied by
grinding wheel.
        For Upcutting the remedies are Analysis of carbon content after annealing, Use of
mechanism for proper lubrication, Automation, Consistent verification & Adjustment of
chisel angle.

         This define, measure and analyze phase have been completed using above
mentioned tools. Further in improve phase the remedies which have been suggested will
give a significant reduction in rejection. The control phase can be implemented once the
initial set of result is obtained. This paper gives initial definition and theory of six sigma
based on grounded theory approach. Although Six Sigma builds off prior
qualitymanagement practices and principles, it offers a newstructure for improvement.
The structural differencessimultaneously promote both more control and explorationin
improvement efforts. Some organizations mayfind benefit from the Six Sigma approach
because it fitstheir organizational needs better.Academics need to better understand Six
Sigma sothat they do not overhype it or too quickly dismiss it asnothing new. It proposes
a rigorous base definition of Six Sigma from the literature and field study that can be
used for further research.We differentiate Six Sigma from TQM and other quality
management approaches.


   1. Roger G. Schroeder, Kevin Linderman, Charles Liedtke, Adrian S. Choo, Six
      Sigma: Definition and underlying theory in Journal of Operations Management
      26 (2008) 536–554
   2. SatyaS.Chakravorty _ Six Sigma programs: An implementation model , Int. J.
      Production Economics
   3. Pete Pande,Larry HolppWhat is Six Sigma ?
   4. BengtKlefsjö (Corresponding Author )and BjarneBergquist, Rick L. Edgeman ,
      Six Sigma and Total Quality Management: differentday, same soup? In Int. J. Six
      Sigma and Competitive Advantage, Vol. x.


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