Six Sigma (6σ) is a set of techniques and tools for process improvement. It is a methodology used for eliminating defects in a product, process or a particular service at a rate of 3.4 Defects Per Million Opportunities. In this document, basic of Six Sigma is highlighted, sigma process calculation is done and various metrics and belts are discussed at the end.

1. SIX SIGMA
What you need to Know
MANIRAFASHA Cedrick
DesiCrew Solutions Private Limited
IIT – Madras Research Park, Tharamani, Chennai
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2. “Measurement is the first step that leads to
control and eventually to improvement.
If you can’t measure something,
you can’t understand it.
If you can’t understand it,
you can’t control it.
If you can’t control it,
you can’t improve it.”
- H. James Harrington
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3. What is Six Sigma
• Methodology
• Metric
• Management System
• Sigma – Standard Deviation which
measures variability
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4. Why Six Sigma
• Improve capability of a business
process
• Improve skills and techniques within an
organization
• Eliminating defects or variation in a
process
• Delivery Excellence
• Management Discipline
• Eliminates Hidden Factory
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5. Why Six Sigma (Contd)
• Improve Customer Loyalty
• Time management
• No change in Project scope
• Employee motivation
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6. Where to use Six Sigma
• Administration
• Management
• Service
• Design
• IT
• HRM
• Production
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7. Six Sigma Metrics
• Defects Per Unit (DPU)
• Defects Per Million Opportunities
(DPMO)
• Parts per Million Defective (PPM)
• A defect is failure of a company to meet
customer’s expectations
• It takes one defect to create a defective
product but a single defective product
can have many defects.
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8. Six Sigma Metrics
• DPMO is a measure of number of
errors occurring in a business or
process
• PPM is average number of defectives
observed in 1 million parts
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9. DPU/DPMO/PPM
• DPU= Number of Defects/Number of
units produced
• DPMO= DPU /Defects Opportunities
* 1000000
• PPM = Defective/Number of Units
*1000000
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10. Sigma Types
Sigma DPMO Defects (%) Yield (%)
1 691462 69 31
2 308538 31 69
3 66807 6.7 93.3
4 6210 0.6 99.3
5 233 0.02 99.98
6 3.4 0.00034 99.99966
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11. Companies using 6 Sigma
• Motorola
• Ericsson
• General Electric
• Sony
• Ford Motor Co.
• CITI bank
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12. Case Study : General Electric
• GE began moving towards a focus on quality in
the late ‘80s with launch of “Work-out”
program.
• CEO Jack Welch, made it a corporate policy to
attain Six Sigma goals by 2000.
• GE required all exempt employees to
undertake a 13-day, 100 hour training in six
sigma methodologies and complete a Six
Sigma project by the end of 1998.
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13. Case Study : General Electric
• The training covered the DMAIC
Procedure
• Mentoring and Leadership played a
major role in achieving this
• In 1995 the average process at GE was
3 sigma
• In 1997 the average reached 3.5 sigma
• Over the course of 5 years of Six Sigma
implementation, GE reported savings of
$12 billion
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14. Example
• A manufacturer of Computer hard
drives creates 83934 hard drives.
The manufacturer performs 8
individual checks per drive to test
quality. During testing, 3432 are
rejected.
Defects : 3432
Opportunities : 83934
Defects opportunities per unit : 8
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15. Example (Contd)
• Total Number of Opportunities =
Opportunities per drive * Total
Number of Drives
• Total Number of Opportunities =
8*83934 = 671472
• DPMO=
3432
671472
*106= 51111.159
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16. Example (Contd)
• Use the following formula in Excel,
NORMSINV(1-(Defects/Total
Opportunities))+1.5
For DPMO equal to 51111.159, we have
4.0682 sigma level with 1.5 shift.
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17. 1.5 Sigma Shift
• 6 Sigma received a tremendous
number of fault-findings that it is based
on fudged numbers.
• With 6 Sigma, there are 2 Defects Per
Billion Opportunities.
• With 3.4 Defects Per Million
Opportunities, there are negligible
defects.
• In reality, 3.4 DPMO corresponds to 4.5
Sigma.
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18. 1.5 Sigma Shift (Contd)
• Based on observed and measured
phenomena from actual experience
rather than theory (Empirical Studies),
– Processes in short term deal with only
normal process variation
– Process in long term deal with special
process variation
• Thus, Short term 6 Sigma = Long Term
4.5 Sigma + Compensation Factor 1.5
Sigma Shift
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19. 3 Sigma Vs 6 Sigma
• With 3 sigma there can be 200000
incorrect drug prescription per year
whereas there can be 1 incorrect drug
prescription every 25 years with 6
sigma.
• With 3 sigma there can be 40500
newborns dropped every one year
whereas there can be 3 newborns
dropped every 1 century with 6 sigma.
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20. PDCA
• Plan-Do-Check-Act
• Repetitive 4-stage model for
Continuous Improvement
• Plan: Define the problem to be
addressed
• Do: Develop and implement a solution
• Check: Confirm the results
• Act: Document results
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21. Six Sigma Methodologies
• Define Measure Analyze Improve
Control (DMAIC)
• Define Measure Analyze Design
Verify (DMADV)
• DMAIC is for improving existing
processes
• DMADV is for creating new
product/process
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22. DMAIC
• Define : Degree of Success/Failure
• Measure : Establish Leadership
Commitment
• Analyze : Gaps between current
process and goals
• Improvement : Monitoring / Training
• Control : Problems are stopped from
recurring / Audit / Incentives
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23. DMADV
• Design: Details / Optimization/
Simulations/ Verification
• Verify: Verify design/ Launch Pilot/
Implement Process/ Train Process
Owners/ Handover to Process
Owners
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24. Levels of Six Sigma
• White Belt
• Yellow Belt
• Green Belt
• Black Belt
• Master Black Belt
• Champion
• Executive Leadership
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25. White / Yellow Belt
• White Belt: Not fully recognized
(Basic)
• Yellow Belt: Basic improvement/
Does not lead projects/
PDCA/Introduction to Process
Management/ Support Staff
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26. Green Belt
• Enhanced Problem Solving Skills
• DMAIC
• Successfully Deploy Six Sigma
Techniques
• Lead Small Scale Projects
• Work under Black Belt
• Lead Planning Teams
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27. Black Belt
• Leadership : Project Team Leader
• Assign Team Members with Roles and
Responsibilities
• Complete understanding of DMAIC
and DMADV
• Change agents
• Full Time
• Project Execution
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28. Master Black Belt (MBB)
• Deep Expertise and Knowledge Base
in the tools and Methods of Six
Sigma
• Create a Plan for Change
Management within an Organization
• Recruit and Train Green and Black
Belts
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29. Champion
• Senior Manager
• Mentoring other Black Belts
• Quality Leader
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30. Executive Leadership
• CEO
• Set up Vision for Six Sigma
• Choose Champions
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31. Thank You
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