1. ICETME-2013
4TH – 5TH JANAUARY,2013
SIX SIGMA: DMAIC APPROACH A CASE
STUDY
Prashant Uttarkar
B.E Production
(prashant@lohaispaat.com)
Loha Ispaat Ltd Vill, Ransai, Taluka Khalapur, Dist. Raigad, Maharashtra-410206
G H Patel College of Engg. & Tech.
International Conference On Emerging Trends In Mechanical Engg.
2. SIX SIGMA: DMAIC APPROACH A
CASE STUDY
1. INTRODUCTION
2. CASE STUDY: MINIMIZE THE CAMBER PROBLEM BY
USING DMAIC METHODOLOGY.
DMAIC (Define – Measure – Analyze – Improve – Control)
3. CONCLUSION
4. REFERENCES
3. Introduction
Six Sigma is a quality improvement programme with a goal to reduce
the number of defects to as low as 3.4 parts per million.
The DMAIC approach of Six Sigma is a systematic methodology utilizing
training, measurement and data analysis tools to identify the root causes and
also eliminate causes for improving the current process and thus achieving
better results.
Sigma
Level
Defects per Million Opportunities
1 697,672
2 308,770
3 66,810
4 6,209
5 232
6 3.4
4. 1) Providing Customer Satisfaction through the total
involvement of ALL employees…
…Making Line Graphs move in the direction you
want them to go.
Target
GOOD
CustomerSatisfaction
Year
Six Sigma is all about…
2)…Or put another way…
Line Graphs Help Us Understand Our Performance
8. Define
In this case study we consider the Accord Engg. Complaint.
The main goal of this case study is to minimize the Camber
Problems which create from Silting Line during processing
material. The camber defect measured on Cut-To-Length line
more effectively/accurately.
The main activities of define phase are to
Define the project boundary by SIPOC (Supplier, Input,
Process, Output,Customer) analysis.
Prepare Critical to Quality (CTQ) specification table.
9. Table 1:- Process Mapping (SIPOC) Of Customer Complaint Analysis
SUPPLIER INPUT PROCESS OUTPUT CUSTOMER
Customer Complaint-- Letter, E-Mail
Resolution Of
Customer
Complaints
Closed
Complaints
Confirmation
From Customer
Customer
Customer
Care
Discussion With Customer,
Action Plan, Repair
Supplier Raw Material As Per Grades
QA Compilation & Follow Up
Meeting
10. Table 2:- Step to Customer Complaint Analysis
Complaint
Reporting/MOM
Analysis Of
Complaint Data
Identification Of
Root Causes And
Corrective Action
Implement
Corrective
Actions
Weekly Meeting
Follow Up
Need CTQ
Operational Definition Of
Measure
Defect Definition KANO Status
Zero complaint Camber
4 M (Man, Method,
Machine, Material)
1 mm per 1m
Accepted
Must be
Table 3: CTQ Specification
11. Measure & Analyze
Data collection plan and identification of stratification factors.
Collection of information on defects.
Analysis of camber reading data for Sigma level estimation and
Cpk valve.
Initial Process analysis based on the stratification factors.
13. Table 4: Analysis Of Variance (ANOVA)
No. of sheet
Observed (o) 17
Expected (e) 6
Deviation (o - e) 11
Deviation2 (d2) 121
d2/e 20.16666667
Chi-Square Test 20.16666667
Degrees of Freedom (df) 8
Probability (p) 0.01
Cpk valve is 0.742. Which is below 1.33 values?
If the p value for the calculated 2 is p < 0.05, reject your hypothesis,
and conclude that some factor other than chance is operating for the
deviation to be so great.
14. Improve and Control
The following root causes were finally selected for improvement.
1. MATERIAL: - CRCA COIL.
2. MACHINE: - Incorrect Gap clearance (Vertical) by operator, Over arm
Separator Disc problem, Uneven size of KNIFES and Rubber.
3. METHOD: - Incorrect Gap clearance (Vertical) by operator, Improper
Processing Parameters, to much loop kept by M/c Operator.
4. MAN: - More No of Cuts planned by Planning Dept, Over arm Separator
Disc problem, Uneven size of KNIFES and Rubber.
15. Root Cause
Counter Measure Target Date Status
Material
Cold Roll Close Annealing (CRCA) Coil
1)Material should be free
from waviness, Bend
Wrinkles 2)
Mention Critical
requirement while
preparing the Purchase
Order
Implementation in next lot as per Supplier.
About
Supplied Raw
Material Loha
informed to
Supplier and
ESSAR person
visited to Loha
and check the
material and
accepted the
Loha
complaint
about
WAVINESS
Material should be free
from Edge Buckling
3) Mention Critical
requirement while
preparing the Purchase
Order
Implementation in next lot as per Supplier.
4)Material free from
BOW
Implementation in next lot as per supplier.
Root Cause
Counter Measure Target Date Status
Next
Target
Date
Machine/Measuring Equipments
Incorrect Gap clearance (Vertical)by operator
Quality Dept will
check the setting
og Leveler
immediately Training Given to M/c. Operator
immediatel
y
Over arm Separator Disc problem
To replace/Regrind
Over arm
separator Disc.
immediately
Indented given to purchase for
procurement of Over arm Separator Disc.
8 weeks
Uneven size of KNIFES and Rubber
Maintain proper
size of KNIFES and
RUBBER
immediately Check the Cutting Tools before slitting
immediatel
y
Root Cause
Counter Measure Target Date Status Next Target Date
Method
Incorrect Gap clearance (Vertical)by operator
Effective training given to
operator on set of
vertical clearance
Immediately
Training Given to M/c.
Operator
Immediately
Improper Processing Parameters Set operating Parameter Immediately Immediately
Too much loop kept by M/c Operator
Effective proper looping
System while operating
M/c
Immediately Immediately
Man Counter Measure Target Date Status Next Target Date
More No of Cuts planned by Planning Dept
Plan to give minimum cut as Per M/c
Design
Immediately
Plan to give
minimum cut as
Per M/c Design
Immediately
No Inspection by Line Quality Dept
Line Quality Inspector will Inspect
material for camber frequently
Immediately Instruction given Immediately
Misfeeds, off-center hits, and inadequate transfer webbing Adjust Centre properly Immediately Training Given Immediately
16. Min 0.70
Max 1.50
Avg 0.98
STDEV 0.23
6* STDEV 1.395
Cpk 2.868
CpkL 1.409
CpkU 0.312
Table 6 :Analysis Of Variance (ANOVA)
No. of Sheet
Observed (o) 1120
Expected (e) 1104
Deviation (o - e) 16
Deviation2 (d2) 256
d2/e 0.2318841
Chi-Square Test 0.2318841
Degrees of Freedom (df) 2
Probability (p) 0.9
-0.5
0
0.5
1
1.5
2
0.0 2.0 4.0 6.0 8.0
Series1
Fig3: Process Capability curve
• We obtain a Cpk valve 2.868, which is above 1.33 values.
• S.D = 0.23, SIGMA VALVE=1.395. & p > 0.05, accept your hypothesis.
• A p value is 0.9, means that there is a 90% probability that any deviation from expected is due to chance only.
• This is within the range of acceptable deviation.
19. Conclusion
Six Sigma saves companies money and it makes sense to produce a
product or service with no defects by doing it right the first time.
Six Sigma methodologies provide a framework, and importantly a
strongly branded corporate initiative, for an organization to:
Train Its People To Focus On Key Performance Areas
Understand Where The Organization Wants To Go (Its Strategy, Related To Its
Market-place)
Understand The Services That The Organization's Customers Need Most
Understand And Better Organize Main Business Processes That Deliver These
Customer Requirements
20. REFERENCES
1. M, Mahajan, 2003, “Statistical Quality Control”, Dhanpat Rai and Co. (p Ltd), Delhi.
2. Greg Brue, 2003, “Design For Six Sigma”, Tata McGraw-Hill, New Delhi.
3. Matti Mottonen, Pekka Belt, Janne Harkonen, Harri Haapasalo and Pekka
Kess,”Manufacturing Process Capability and Specification Limits”, Department of
Industrial Engineering and Management, University of Oulu, Finland
4. Kimberly Brown-Harden, “How Six Sigma Increases Customer Satisfaction”,
University of Indianapolis.
5. Carlos Riesenberger,”Application of the Six Sigma methodology in customer
complaints management”, University of Minho, Dep. of Production and Systems,
School of Engineering,Campus de Gualtar- 4710-057 Braga, Portugal.
6. Sanjit Ray, Prasun Das, Bidyut Kr. Bhattacharya,”Improve Customer Complaint
Resolution Process Using Six Sigma”, SQC and OR Division, 8th Mile, Mysore Road,
Bangalore 560 059, Karnataka, India.
7. Resit Unal and Edwin B. Dean, “Taguchi Approach to Design Optimazation for
Quality and Cost: An Overview”, Presented at the 1991 Annual Conference of the
international Society of Parametric Analysis.
8. Donald W. Benbow and T.M Kudial, 2008, “The Certified Six Sigma Black Belt
Handbook”, Pearson Education, Delhi.
9. Steve Schmidt, PhD, Air Academy Associates, LLC and Ken Case, PhD, Oklahoma
State University “Communicating Design of Experiments (Doe) To Non-Statisticians”.
10. Kai Yang and Basem S. Ei-haik, 2003, “Design for Six Sigma: A Roadmap for Product
Development”, McGraw-hill Professional. ETC.
11. Yang, Ching-Chow,”Six sigma and Total Quality Management”, Department of
Industrial and Systems Engineering, hung Yuan Christian University, Taiwan, R.O.C.
