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What is Six Sigma?
Kingsley Nwagu
University of Cumbria
Feb 2012
Basics
 A new way of doing business
 Wise application of statistical tools within
a structured methodology
 Repeated application of strategy to
individual projects
 Projects selected that will have a
substantial impact on the ‘bottom line’
A scientific and practical method to achieve
improvements in a company
Scientific:
• Structured approach.
• Assuming quantitative data.
Practical:
• Emphasis on financial result.
• Start with the voice of the customer.
“Show me
the data”
”Show me
the money”
Six Sigma
Six Sigma
Methods Production
Design
Service
Purchase
HRM
Administration
Quality
Depart.
Management
M & S
IT
Where can Six Sigma be applied?
Knowledge
Management
The Six Sigma Initiative
integrates these efforts
‘Six Sigma’ companies
 Companies who have successfully
adopted ‘Six Sigma’ strategies include:
GE “Service company” - examples
 Approving a credit card application
 Installing a turbine
 Lending money
 Servicing an aircraft engine
 Answering a service call for an appliance
 Underwriting an insurance policy
 Developing software for a new CAT product
 Overhauling a locomotive
“the most important initiative GE has
ever undertaken”. Jack Welch
Chief Executive Officer
General Electric
• In 1995 GE mandated each employee to work towards
achieving 6 sigma
• The average process at GE was 3 sigma in 1995
• In 1997 the average reached 3.5 sigma
• GE’s goal was to reach 6 sigma by 2001
• Investments in 6 sigma training and projects reached
45MUS$ in 1998, profits increased by 1.2BUS$
General Electric
“At Motorola we use statistical methods daily
throughout all of our disciplines to synthesize an
abundance of data to derive concrete actions….
How has the use of statistical methods within
Motorola Six Sigma initiative, across disciplines,
contributed to our growth? Over the past decade we
have reduced in-process defects by over 300 fold,
which has resulted in cumulative manufacturing cost
savings of over 11 billion dollars”*.
Robert W. Galvin
Chairman of the Executive Committee
Motorola, Inc.
MOTOROLA
*From the forward to MODERN INDUSTRIAL STATISTICS by Kenett and Zacks, Duxbury, 1998
Positive quotations
 “If you’re an average Black Belt, proponents say
you’ll find ways to save $1 million each year”
 “Raytheon figures it spends 25% of each sales
dollar fixing problems when it operates at four
sigma, a lower level of efficiency. But if it raises
its quality and efficiency to Six Sigma, it would
reduce spending on fixes to 1%”
 “The plastics business, through rigorous Six
Sigma process work , added 300 million pounds
of new capacity (equivalent to a ‘free plant’),
saved $400 million in investment and will save
another $400 million by 2000”
Negative quotations
 “Because managers’ bonuses are tied to Six
Sigma savings, it causes them to fabricate
results and savings turn out to be phantom”
 “Marketing will always use the number that
makes the company look best …Promises are
made to potential customers around capability
statistics that are not anchored in reality”
 “ Six Sigma will eventually go the way of the
other fads”
Barrier #1: Engineers and managers are not interested in
mathematical statistics
Barrier #2: Statisticians have problems communicating with
managers and engineers
Barrier #3: Non-statisticians experience “statistical anxiety”
which has to be minimized before learning can take place
Barrier # 4: Statistical methods need to be matched to
management style and organizational culture
Barriers to implementation
Technical
Skills
Soft Skills
Statisticians
Master
Black Belts
Black Belts
Quality Improvement
Facilitators
BB
MBB
Reality
 Six Sigma through the correct application
of statistical tools can reap a company
enormous rewards that will have a positive
effect for years
or
 Six Sigma can be a dismal failure if not
used correctly
 ISRU, CAMT and Sauer Danfoss will
ensure the former occurs
Six Sigma
 The precise definition of Six Sigma is not
important; the content of the program is
 A disciplined quantitative approach for
improvement of defined metrics
 Can be applied to all business
processes, manufacturing, finance and
services
Focus of Six Sigma*
Accelerating fast breakthrough
performance
Significant financial results in 4-8
months
Ensuring Six Sigma is an extension of
the Corporate culture, not the program
of the month
Results first, then culture change!
*Adapted from Zinkgraf (1999), Sigma Breakthrough
Technologies Inc., Austin, TX.
Six Sigma: Reasons for Success
The Success at Motorola, GE and
AlliedSignal has been attributed to:
 Strong leadership (Jack Welch, Larry
Bossidy and Bob Galvin personally involved)
 Initial focus on operations
 Aggressive project selection (potential
savings in cost of poor quality >
$50,000/year)
 Training the right people
The right way!
Plan for “quick wins”
 Find good initial projects - fast wins
Establish resource structure
 Make sure you know where it is
Publicise success
 Often and continually - blow that trumpet
Embed the skills
 Everyone owns successes
The Six Sigma metric
Consider a 99% quality level
 5000 incorrect surgical operations per
week!
 200,000 wrong drug prescriptions per
year!
 2 crash landings at most major airports
each day!
 20,000 lost articles of mail per hour!
Not very satisfactory!
 Companies should strive for ‘Six Sigma’
quality levels
 A successful Six Sigma programme can
measure and improve quality levels across
all areas within a company to achieve
‘world class’ status
 Six Sigma is a continuous improvement
cycle
Scientific method (after Box)
INDUCTION INDUCTION
DEDUCTION DEDUCTION
Data
Facts
Theory
Hypothesis
Conjecture
Idea
Model
Check
Plan
DoAct
23
Improvement cycle
 PDCA cycle
Plan
Do
Check
Act
Prioritise (D)
Measure (M)
Interpret
(D/M/A)
Problem (D/M/A)
solve
Improve (I)
Hold
gains (C)
Alternative interpretation
Statistical background
Target = m
Some Key measure
+/- 3s
Statistical background
Target = m
‘Control’ limits
+/- 3s
LSL USL
Statistical background
Required Tolerance
Target = m
+/- 3s
+/- 6s
LSL USL
Statistical background
Tolerance
Target = m
Six-Sigma
+/- 3s
+/- 6s
LSL USL
ppm
1350
ppm
1350
Statistical background
Tolerance
Target = m
+/- 3s
+/- 6s
LSL USL
ppm
0.001
ppm
1350
ppm
1350
ppm
0.001
Statistical background
Tolerance
Target = m
Statistical background
 Six-Sigma allows for un-foreseen
‘problems’ and longer term issues
when calculating failure error or
re-work rates
Allows for a process ‘shift’
LSL
0 ppm ppm
3.4
1.5s
USL
ppm
3.4ppm
66803
m
+/- 6s
Statistical background
Tolerance
Performance Standards
2
3
4
5
6
308537
66807
6210
233
3.4
s PPM
69.1%
93.3%
99.38%
99.977%
99.9997%
Yield
Process
performance
Defects per
million
Long term
yield
Current standard
World Class
Number of processes 3σ 4σ 5σ 6σ
1
10
100
500
1000
2000
2955
93.32
50.09
0.1
0
0
0
0
99.379
93.96
53.64
4.44
0.2
0
0
99.9767
99.77
97.70
89.02
79.24
62.75
50.27
99.99966
99.9966
99.966
99.83
99.66
99.32
99.0
First Time Yield in multiple stage process
Performance standards
Benefits of 6s approach w.r.t. financials
s-level Defect rate
(ppm)
Costs of poor quality Status of the
company
6 3.4 < 10% of turnover World class
5 233 10-15% of turnover
4 6210 15-20% of turnover Current standard
3 66807 20-30% of turnover
2 308537 30-40% of turnover Bankruptcy
Financial Aspects
Six Sigma and other
Quality programmes
Comparing three recent developments
in “Quality Management”
 ISO 9000 (-2000)
 EFQM Model
 Quality Improvement and Six
Sigma Programs
ISO 9000
 Proponents claim that ISO 9000 is a
general system for Quality Management
In fact the application seems to involve
 an excessive emphasis on Quality Assurance,
and
 standardization of already existing systems
with little attention to Quality Improvement
 It would have been better if improvement
efforts had preceded standardization
Critique of ISO 9000
 Bureaucratic, large scale
 Focus on satisfying auditors, not customers
 Certification is the goal; the job is done when
certified
 Little emphasis on improvement
 The return on investment is not transparent
 Main driver is:
 We need ISO 9000 to become a certified supplier,
 Not “we need to be the best and most cost effective
supplier to win our customer’s business”
 Corrupting influence on the quality profession
EFQM Model
 A tool for assessment: Can measure where we
are and how well we are doing
 Assessment is a small piece of the bigger
scheme of Quality Management:
 Planning
 Control
 Improvement
 EFQM provides a tool for assessment, but no
tools, training, concepts and managerial
approaches for improvement and planning
The “Success” of Change
Programs?
“Performance improvement efforts …
have as much impact on
operational and financial results as a
ceremonial rain dance has on the weather”
Schaffer and Thomson,
Harvard Business Review (1992)
Change Management:
Two Alternative Approaches
Activity Centered
Programs
Result Oriented
Programs
Change
Management
Reference: Schaffer and Thomson, HBR, Jan-Feb. 1992
Activity Centered Programs
 Activity Centered Programs: The pursuit of
activities that sound good, but contribute little
to the bottom line
 Assumption: If we carry out enough of the
“right” activities, performance improvements
will follow
 This many people have been trained
 This many companies have been certified
 Bias Towards Orthodoxy: Weak or no
empirical evidence to assess the relationship
between efforts and results
No Checking with Empirical Evidence, No
Learning Process
ISO 9000
Data
Hypothesis
Deduction Induction
An Alternative:
Result-Driven Improvement Programs
 Result-Driven Programs: Focus on
achieving specific, measurable, operational
improvements within a few months
 Examples of specific measurable goals:
 Increase yield
 Reduce delivery time
 Increase inventory turns
 Improved customer satisfaction
 Reduce product development time
Result Oriented Programs
 Project based
 Experimental
 Guided by empirical evidence
 Measurable results
 Easier to assess cause and effect
 Cascading strategy
Why Transformation
Efforts Fail!
 John Kotter, Professor, Harvard Business
School
 Leading scholar on Change Management
 Lists 8 common errors in managing
change, two of which are:
• Not establishing a sense of urgency
• Not systematically planning for and
creating short term wins
Six Sigma Demystified*
Six Sigma is TQM in disguise, but this
time the focus is:
 Alignment of customers, strategy, process
and people
 Significant measurable business results
 Large scale deployment of advanced
quality and statistical tools
 Data based, quantitative
*Adapted from Zinkgraf (1999), Sigma Breakthrough
Technologies Inc., Austin, TX.
Keys to Success*
 Set clear expectations for results
 Measure the progress (metrics)
 Manage for results
*Adapted from Zinkgraf (1999), Sigma Breakthrough
Technologies Inc., Austin, TX.
Key personnel in
successful Six Sigma
programmes
Black Belts
 Six Sigma practitioners who are employed
by the company using the Six Sigma
methodology
 work full time on the implementation of problem
solving & statistical techniques through projects
selected on business needs
 become recognised ‘Black Belts’ after
embarking on Six Sigma training programme
and completion of at least two projects which
have a significant impact on the ‘bottom-line’
Black Belt required resources
-Training in statistical methods.
-Time to conduct the project!
-Software to facilitate data analysis.
-Permissions to make required changes!!
-Coaching by a champion – or external support.
Black Belt requirements
In other words the Black Belt is
-Empowered.
-In the sense that it was always meant!
-As the theroists have been saying for years!
Black Belt role!
Champions or ‘enablers’
 High-level managers who champion Six
Sigma projects
 they have direct support from an
executive management committee
 orchestrate the work of Six Sigma Black
Belts
 provide Black Belts with the necessary
backing at the executive level
Further down the line - after initial Six Sigma
implementation package
 Master Black Belts
 Black Belts who have reached an acquired level
of statistical and technical competence
 Provide expert advice to Black Belts
 Green Belts
 Provide assistance to Black Belts in Six Sigma
projects
 Undergo only two weeks of statistical and
problem solving training
Six Sigma instructors (ISRU)
 Aim: Successfully integrate the Six Sigma
methodology into a company’s existing culture
and working practices
 Key traits
 Knowledge of statistical techniques
 Ability to manage projects and reach closure
 High level of analytical skills
 Ability to train, facilitate and lead teams to
success, ‘soft skills’
Six Sigma training
package
Aim of training package
To successfully integrate Six Sigma
methodology into Sauer Danfoss’
culture and attain significant
improvements in quality, service and
operational performance
DMAIC
Define Select a project
Measure Prepare for assimilating information
Analyze Characterise the current situation
Improve Optimize the process
Control Assure the improvements
Six-Sigma - A “Roadmap” for improvement
Training (1 week)
Work on project
(3 weeks)
Review
Define
Measure
Analyze
Improve
Control
Throughput time project
4 months (full time)
Example of a Classic Training strategy
ISRU program content
 Week 1 - Six Sigma introductory week
(Deployment phase)
 Weeks 2-5 - Main Black Belt training
programme
 Week 2 - Measurement phase
 Week 3 - Analysis phase
 Week 4 - Improve phase
 Week 5 - Control phase
 Project support for Six Sigma Black Belt
candidates
 Access to ISRU’s distance learning facility
Draft training schedule
No. Black Belt work package tasks Start End Duration
Jan 2003 Feb 2003 Mar 2003 Apr 2003 May 2003 Jun 2003 Jul 2003
1/5 1/12 1/19 1/26 2/2 2/9 2/16 2/23 3/2 3/9 3/16 3/23 3/30 4/6 4/13 4/20 4/27 5/4 5/11 5/18 5/25 6/1 6/8 6/15 6/22 6/29 7/6 7/13 7/20 7/27
1 1d03/02/0303/02/03Champions Day
2 3d06/02/0304/02/03Intial 3-day Black belt sessions
3 1d07/02/0307/02/03Administration Day
5 1w21/02/0317/02/03
Black Belt training (Measurement
phase)
12 2d30/07/0329/07/03Project support (Follow up)
7 1w18/04/0314/04/03Black Belt training (Analysis phase)
9
11
1w30/05/0326/05/03Black Belt training (Improvement phase)
1w11/07/0307/07/03Black Belt training (Control phase)
6 1d25/03/0325/03/03Project support (Workshop2)
8 1d06/05/0306/05/03Project support (Workshop 3)
4 1d11/02/0311/02/03Project support (Workshop 1)
10 1d17/06/0317/06/03Project support (Workshop 4)
Training programme delivery
 Lectures supported by appropriate technology
 Video case studies
 Games and simulations
 Experiments and workshops
 Exercises
 Defined projects
 Delegate presentations
 Homework!
Measure
Analyze
Improve
Control
Define
5 weeks of training
Deployment (Define) phase
 Topics covered include
 Team Roles
 Presentation skills
 Project management skills
 Group techniques
 Quality
 Pitfalls to Quality Improvement projects
 Project strategies
 Minitab introduction
Measurement phase
Topics covered include:
 Quality Tools
 Risk Assessment
 Measurements
 Capability & Performance
 Measurement Systems Analysis
 Quality Function Deployment
 FMEA
Example - QFD
A method for meeting customer
requirements
Uses tools and techniques to set product
strategies
Displays requirements in matrix diagrams,
including ‘House of Quality’
Produces design initiatives to satisfy
customer and beat competitors
House Of Quality
6. Technical assessment and
target values
1. Customer
requirements
4. Relationship
matrix
3. Product
characteristics
Importance
2. Competitive
assessment
5. Tradeoff
matrix
Lead-times - the time to market and time
to stable production
Start-up costs
Engineering changes
QFD can reduce
Analysis phase
Topics include:
 Hypothesis testing
 Comparing samples
 Confidence Intervals
 Multi-Vari analysis
 ANOVA (Analysis of Variance)
 Regression
Improvement phase
 Topics include:
 History of Design of Experiments (DoE)
 DoE Pre-planning and Factors
 DoE Practical workshop
 DoE Analysis
 Response Surface Methodology (Optimisation)
 Lean Manufacturing
Example - Design of Experiments
What can it do for you?
Minimum cost Maximum output
What does it involve?
Brainstorming sessions to identify
important factors
Conducting a few experimental trials
Recognising significant factors which
influence a process
Setting these factors to get maximum
output
Control phase
 Topics include:
 Control charts
 SPC case studies
 EWMA
 Poka-Yoke
 5S
 Reliability testing
 Business impact assessment
Example - SPC (Statistical Process Control)
- reduces variability and keeps the process stable
Disturbed process
Natural process
Temporary
upsets
Natural boundary
Natural boundary
Results of SPC
An improvement in the process
Reduction in variation
Better control over process
Provides practical experience of
collecting useful information for analysis
Hopefully some enthusiasm for
measurement!
Project support
 Initial ‘Black Belt’ projects will be considered in
Week 1 by Executive management committee,
‘Champions’ and ‘Black Belt’ candidates
 Projects will be advanced significantly during
the training programme via:
 continuous application of newly acquired statistical
techniques
 workshops and on-going support from ISRU and CAMT
 delivery of regular project updates by ‘Black Belt’
candidates
Black Belt
Training
Application
Review
ISRU
ISRU,
Champion
ISRU,
Champion
Project execution
Traditional Six Sigma
-Project leader is obliged to
make an effort.
-Set of tools.
-Focus on technical knowledge.
-Project leader is left to his own
devices.
-Results are fuzzy.
-Safe targets.
-Projects conducted “on the
side”.
-Black Belt is obliged to
achieve financial results.
-Well-structured method.
-Focus on experimentation.
-Black Belt is coached by
champion.
-Results are quantified.
-Stretched targets.
-Projects are top priority.
Conducting projects
The right support
+
The right projects
+
The right people
+
The right tools
+
The right plan
=
The right results
Champions Role
• Communicate vision and progress
• Facilitate selecting projects and people
• Track the progress of Black Belts
• Breakdown barriers for Black Belts
• Create supporting systems
Champions Role
• Measure and report Business Impact
• Lead projects overall
• Overcome resistance to Change
• Encourage others to Follow
Define
Select:
- the project
- the process
- the Black Belt
- the potential savings
- time schedule
- team
Project selection
Projects may be selected according to:
1. A complete list of requirements of customers.
2. A complete list of costs of poor quality.
3. A complete list of existing problems or targets.
4. Any sensible meaningful criteria
5. Usually improves bottom line - but exceptions
Project selection
Key Quality Characteristics
“CTQs”
How will you measure them?
How often?
Who will measure?
Is the outcome critical or important
to results?
Outcome Examples
Reduce defective parts per million
Increased capacity or yield
Improved quality
Reduced re-work or scrap
Faster throughput
Key Questions
Is this a new product - process?
Yes - then potential six-sigma
Do you know how best to run a
process?
No - then potential six-sigma
Key Criteria
Is the potential gain enough - e.g. -
saving > $50,000 per annum?
Can you do this within 3-4 months?
Will results be usable?
Is this the most important issue at the
moment?
Why is ISRU an effective
Six Sigma practitioner?
Because we are experts in the application
of industrial statistics and managing the
accompanying change
We want to assist companies in improving
performance thus helping companies to
greater success
We will act as mentors to staff embarking
on Six Sigma programmes
Reasons
INDUSTRIAL STATISTICS
RESEARCH UNIT
We are based in the School of Mechanical and
Systems Engineering, University of Newcastle upon
Tyne, England
Mission statement
"To promote the effective and
widespread use of statistical
methods throughout European
industry."
The work we do can be broken
down into 3 main categories:
 Consultancy
 Training
 Major Research Projects
All with the common goal of promoting quality
improvement by implementing statistical
techniques
Consultancy
We have long term one to one consultancies
with large and small companies, e.g.
Transco
Prescription Pricing Agency
Silverlink
To name but a few
Training
In-House courses
 SPC
 QFD
 Design of Experiments
 Measurement Systems Analysis
On-Site courses
 As above, tailored courses to suit the company
 Six Sigma programmes
European projects
 The Unit has provided the statistical input into
many major European projects
Examples include -
 Use of sensory panels to assess butter quality
 Using water pressures to detect leaks
 Assessing steel rail reliability
 Testing fire-fighter’s boots for safety
European projects
 Eurostat - investigating the multi-dimensional
aspects of innovation using the Community
Innovation Survey (CIS) II
- 17 major European countries involved -
determining the factors that influence
innovation
 Certified Reference materials for assessing
water quality - validating EC Laboratories
 New project - ‘Effect on food of the taints
and odours in packaging materials’
Typical local projects
 Assessment of environmental risks in
chemical and process industries
 Introduction of statistical process control
(SPC) into a micro-electronics company
 Helping to develop a new catheter for
open-heart surgery via designed
experiments (DoE)
 ‘Restaurant of the Year’ & ‘Pub of the Year’
competitions!
Benefits
Better monitoring of processes
Better involvement of people
Staff morale is raised
Throughput is increased
Profits go up
Examples of past successes
Down time cut by 40% - Villa soft drinks
Waste reduced by 50% - Many projects
Stock holding levels halved - Many
projects
Material use optimised saving £150k pa -
Boots
Expensive equipment shown to be
unnecessary - Wavin