Six Sigma is a data-driven methodology for process improvement that aims to reduce defects. It follows the DMAIC cycle of define, measure, analyze, improve, and control. The methodology was developed by Motorola in the 1980s and focuses on minimizing process variation to produce no more than 3.4 defects per million opportunities. Projects use belts ranging from Green to Black to Master Black Belt to implement Six Sigma techniques and achieve a process capability of 1.5 or better. While effective for large companies, Six Sigma can be difficult for small businesses to implement due to infrastructure and training costs.

1. SIX SIGMA

2.  Six Sigma is a disciplined, statistical-based,
data-driven approach and continuous
improvement methodology for eliminating
defects in a product, process or service.

3. BASICS OF SIX SIGMA
 Six Sigma Basics.
 Six Sigma is the most effective methodology
available for improving the performance of
any organization by minimizing the defects in
its products or services.
 The Six Sigma methodology was first
endorsed at Motorola in the mid-1980s.

4. CONCEPT
 Six Sigma is a disciplined, data-
driven approach and methodology for
eliminating defects (driving
toward six standard deviations between the
mean and the nearest specification limit) in
any process – from manufacturing to
transactional and from product to service.

5. HOW IT WORKS
 Six Sigma is a disciplined and quantitative
approach involving setting up a system and
process for the improvement of defined
metrics in manufacturing, service, or financial
processes. ...
 Improvement projects follow a disciplined
process defined by a system of four macro
phases: measure, analyze, improve, control
(MAIC).

6. KEY PRINCIPLES
 Focus on the customer.
 Identify and understand how the work gets
done (the value stream).
 Manage, improve and smooth the process
flow.
 Remove Non-Value-Added steps and waste.
 Manage by fact and reduce variation.

7. LEVELS OF SIX SIGMA
 “Six Sigma” management has several levels
of certification
 They are:
 Champion
 Yellow/Green Belt
 Brown/Black Belt and
 Master Black Belt.
 A Six Sigma Champion is the most basic form of
Six Sigma certification.

8. PHASES OF SIX SIGMA
 It consists of five Phases:
 Define
 Measure
 Analyze
 Improve and
 Control.
 Its called DMAIC

10. SIX SIGMA METHODOLOGY
 Six Sigma - Methodology.
 DMAIC − It refers to a data-driven quality
strategy for improving processes.
 This methodology is used to improve an
existing business process.
 DMADV − It refers to a data-driven quality
strategy for designing products & processes.

11. DMAIC METHODOLOGY

12.  Define - address the identification of specific
processes to be examined
 Measure - record data and use metrics to track
effectiveness and evaluate efficiencies
 Analyze - utilize critical thinking skills to review data
and clarify goals
 Improve - create changes in business processes
geared toward improvement and better alignment
with corporate goals
 Control - build a system of checks and adjustments
for ongoing improvement in production processes

13. DMADV METHODOLOGY

14.  Define - address customer needs in relation to a product or
service
 Measure - involve the use of electronic data collection to
measure customer needs, response to product, or review of
services
 Analyze - utilize metrics to evaluate areas where product or
service can be better aligned to customer goals and needs
 Design - overlap the improvement of business processes that
streamline corporate goals to best meet client and customer
needs
 Verify - build a system of tests and models to check that
customer specifications are being met through on-going
improvements

15. INTRODUCTION
 According to James Harrington, “Six Sigma” is
simply a TQM process that uses process
capability analysis as a way of measuring
progress
 Sigma, is the Greek symbol for the statistical
measurement of dispersion called Standard
Deviation
 It is the best measurement of process variability
because , the smaller the deviation value, the
less variability in the process

16.  The following figure shows a process that is
normally distributed and centered with the
upper and lower specifications limit (USL and
LSL) established at ± 6σ
 For the above, 99.9999998% of the product or
service will be between specifications and the
nonconformance rate will be 0.002 parts per
million or 2 per billion
 The above represents a process capability
index(Cp) of 2.0
 A Cp of 1.33 has been a defacto standard

18. NONCONFORMANCE RATE AND PROCESS
CAPABILITY WHEN THE PROCESS IS CENTERED
Specification
Limit
Percent
Conformance
Nonconforma
nce Rate
(ppm)
Process
Capability
(Cp)
±1 σ 68.7 317300 0.33
±2σ 95.45 485500 0.67
±3σ 99.73 2700 1.00
±4σ 99.9937 63 1.33
±5σ 99.999943 0.57 1.67
±6σ 99.9999998 0.002 2.0

19.  According to the Six Sigma philosophy,
processes rarely stay centered
 The center tends to shift above and below
the target, μ
 The following fig shows a process that is
normally distributed, but has shifted within a
range of 1.5σ above and 1.5σ below the target

21.  For the above, 99.9996600% of the product
or service will be between specifications and
the nonconformance rate will be 3.4ppm.
 This offcenter situation gives a process
capability index (Cpk) of 1.5 with 1.0 being
the defacto standard

22. NONCONFORMANCE RATE AND PROCESS
CAPABILITY WHEN THE PROCESS ID OFFCENTER
±1.5 SIGMA
Specification
Limit
Percent
Conformance
Nonconforma
nce Rate
(ppm)
Process
Capability
(Cpk)
±1σ 30.23 697700 -0.167
±2σ 69.13 308700 0.167
±3σ 93.32 66810 0.500
±4σ 99.3790 6210 0.834
±5σ 99.97670 2330 1.167
±6σ 99.9996600 3.4 1.500

23.  None of the case studies in the literature
have indicated a shift as great as 1.5 σ
 The statistical aspects of six-sigma tell us that we
should reduce the process variability, σ, and try to
keep the process centered on the target, μ

24.  Harry and Schroeder use a methodology called
DMAIC (Define, Measure, Analyze, Improve and
Control)
 Project Approach
 Projects are identified by the amount of savings
they can generate
 Trained personnel
 Small group of individuals use karate
designations- Green Belts, Black Belts and
Master Black Belts

25.  Green Belts- Project Leaders- 5 Days of
class room training
 Black Belts- 160 hrs of classroom instruction
and one-on-one coaching from Master Black
Belts- Help Green Belts
 Master Black Belts provide the technical
leadership and much of the training for the
program

26. PROBLEMS
 Difficult and not very cost effective for small
businesses to develop the required
infrastructure
 High cost of training
 GE- 2 Billion
 In large companies , infrastructure will
become a bureaucracy

27. INDIAN COMPANIES PRACTICING SIX SIGMA
 WIPRO
 TATA STEEL
 TELCO
 ASIAN PAINTS
 L&T SWITCHGEAR
 RELIANCE PATALGANGA
 TVS SUZUKI
 TATA HONEYWELL
 TATA CONSULTANCY