Quality Tools
MTSU
1
The PDSA Cycle
Plan
Act
Do
Study
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2
The Process Improvement
Cycle
Select a
process
Document
Study/document
Evaluate
Seek ways to
Improve it
Implement the
Improved process
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Design an
Improved process
3
Process Improvement Tools
• There are a number of tools that
can be used for problem solving
and process improvement
• Tools aid in data collection and
interpretation, and provide the
basis for decision making
MTSU
4
Seven Basic Quality Tools
1.
2.
3.
4.
5.
6.
7.
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Check sheets
Flowcharts
Scatter diagrams
Histograms
Pareto analysis
Control charts
Cause-and-effect diagrams
5
Check Sheet
Billing Errors
Monday
Wrong Account
Wrong Amount
A/R Errors
Wrong Account
Wrong Amount
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6
Flowchart
Process
Good?
Process
Good?
Process
Process
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7
Scatter Diagram
Variable B
Variable A
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8
Histogram
frequency
A
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B
C
D
E
9
80% of the
problems
may be
attributed to
20% of the
causes.
MTSU
Number of defects
Pareto Analysis
Off
Smeared Missing Loose Other
center print
label
10
Control Chart
1020
UCL
1010
1000
990
LCL
980
970
0
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1
2
3
4
5
6
7
8
9 10 11 12 13 14 15
11
Cause-and-Effect Diagram
Methods
Materials
Cause
Cause
Cause
Cause
Cause
Cause
Environment
Effect
Cause
Cause
Cause
People
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Cause
Cause
Cause
Equipment
12
Tracking Improvements
UCL
UCL
UCL
LCL
LCL
LCL
Process centered
Process not centered and stable
and not stable
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Additional improvements
made to the process
13
Seven Management Tools
1.
2.
3.
4.
5.
6.
7.
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Affinity Diagram
Interrelationship Diagraph
Tree Diagrams
Prioritization Matrices
Matrix Diagram
Process Decision Program Chart
Activity Network Diagram
14
Methods for Generating Ideas
• Brainstorming
• Quality circles
• Interviewing
• Benchmarking
• 5W2H
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15
A Brief History of Quality
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16
America Re-discovers Deming
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17
… and Juran
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18
Rediscovering the Gurus
• Deming
– Emphasis on Statistical Control
– 14 Points for Management
• Juran
– Quality Planning and Analysis
– Managerial Breakthrough
– Quality Control Handbook
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20
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21
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22
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23
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24
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25
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27
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28
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What Types of Companies Can
Benefit from Six Sigma?
• Companies that benefit from structured
organizational improvement
• Companies that need to improve customer
satisfaction
• All types of companies can benefit:
–
–
–
–
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Manufacturing
Service
Non-profit
Educational
32
What is Six Sigma?
A. Customer Focus – Focus on what is
critical to customers
B. Data Driven – Extensive use of
statistical tools
C. Robust Methodology – Tools plus
implementation methods to make
success more likely
MTSU
33
What is Six Sigma?
Key Concepts
1. Critical to Quality: What attributes are
most important to the customer?
(CTQ, CTC, CTD)
2. Defect: Failing to deliver what the
customer wants / expects (DPMO)
3. Variation: The level of
unpredictability the customer
experiences
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34
What is Six Sigma?
Key Concepts
5. Process Capability: What your process
can deliver – consistently
6. Stable Operations: Stable ops are
predictable
7. Design for Six Sigma: Designing to
meet customer needs and process
capability
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35
DMADV - DMAIC
Existing Processes
New Processes
Measure
Design
Analyze
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Define
Control
Define
Verify
Measure
Improve
Analyze
36
Statistics Lite
Centered 3s Process
LSL
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USL
37
Statistics Lite
Centered 3s Process
LSL
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s
USL
38
Statistics Lite
Centered 3s Process
LSL
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s
USL
Non-conforming
Product
1,300 DPMO
39
Statistics Lite
Centered 3s Process
LSL
MTSU
s
USL
Non-conforming
Product
2,600 DPMO
40
Statistics Lite
Shifted 3s Process
LSL
s
USL
1.5 s mean shift
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41
Statistics Lite
Shifted 3s Process
LSL
s
USL
Non-conforming
Product
66,800 DPMO
1.5 s mean shift
MTSU
42
Statistics Lite
Shifted 3s Process
Cost to your company – 15-30% of sales
LSL
s
USL
Non-conforming
Product
66,800 DPMO
1.5 s mean shift
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43
Cost of Poor Quality
5-8% of
Sales
Inspection
Overtime
Downtime
Rejects
Rework
Lost sales
Long cycle times
Cost of Capital
Redundant Operations
Expediting costs
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Late delivery
(less obvious)
Lost Opportunity
Lost Customer Loyalty
15-22%
of Sales
Inaccurate Reports
Excessive Planning
44
Statistics Lite
Centered 6s Process
LSL
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s
USL
45
Statistics Lite
Shifted 6s Process
LSL
s
USL
1.5 s mean shift
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46
Statistics Lite
Shifted 6s Process
LSL
s
USL
Non-conforming
Product
3.4 DPMO
1.5 s mean shift
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47
Why Six Sigma?
99% (3.8 Sigma)
99.99966% (6 Sigma)
• 20,000 lost articles of mail per
hour
• Seven articles lost per hour
• 5,000 incorrect surgical
operations per week
• 2 incorrect operations per week
• Two short or long landings at
most major airports each day
• 200,000 wrong drug prescriptions
each year
• No electricity for almost seven
hours each month
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• One short or long landing every
five years
• 70 wrong prescriptions per year
• One hour without electricity every
34 years
48
Six Sigma
Breakthrough Strategy
• Define
• Measure
• Analyze
• Improve
• Control
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49
DMADV - DMAIC
New Processes
Define
Verify
Measure
Design
Analyze
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Existing Processes
Define
Control
Measure
Improve
Analyze
50
Define - Selecting Projects
• The project must relate to customer
satisfaction
• The project’s results must reduce
defects by some threshold amount
• The project should achieve some
threshold of cost savings.
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51
Criteria for Project Selection
• Does it involve recurring events?
• Is the scope narrow?
• Do measures exist?
• Do you have control of the process?
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52
Define Phase, Continued
• If these criteria are met then:
1) Identify the customers involved, both
internal and external to the function.
2) Find out what the customer’s CT’s are
(Critical to Quality, Critical to Delivery,
Critical to Cost, etc).
3) Define the project scope and goals.
4) Map the process to be improved.
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53
Define Phase - Tools
• Project Charter
• Stakeholder
Analysis
• Affinity Diagram
• SIPOC
• Voice of the
Customer
• CT Tree
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• Kano Model
• SWOT Analysis
• Cause-and-Effect
Diagrams
• Supplier
Segmentation
• Project Management
54
Charter
• Problem statement
• Business case
• Goals, milestones,
success criteria, &
deliverables
• Project scope /
boundaries
• Roles & responsibilities
• Stakeholder support /
approval needed
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55
Define Phase
Charter Development
Charter – An agreement between
management and project team members
about what the team will accomplish.
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56
Charter: Providing Direction
You have to be
careful if you
don’t know
where you’re
going, ... because
you might not
get there.
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57
Define Phase
Charter – What it does
• Clarifies expectations (what and why)
• Keeps team focused
– Reduces tampering
– Reduces wandering
– Reduces goal creep
• Transfers ownership from management
to team
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58
Define Phase
Charter – What it does
• Provides overview of purpose
• Describes why you are working on this
project (business case)
• Defines scope of project
• Determines deliverables
• Defines measures of success
• Determines resources available
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59
Business Case
Potential Improvement
Potential Impact
Improve quality
Reduce cost, inventory
Improve OTD
Shortages , inventory 
Select better suppliers
Q, $, LT, reduce inventory
Implement rating system
Improve supply efficiency,
better suppliers
Reduce cost
60
Reduce
price
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Define Phase - Tools
• Project Charter
• Stakeholder
Analysis
• Affinity Diagram
• SIPOC
• Voice of the
Customer
• CT Tree
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• Kano Model
• SWOT Analysis
• Cause-and-Effect
Diagrams
• Supplier
Segmentation
• Project Management
61
SIPOC Example
Suppliers
Ops Mgt
Buyers
Engrg.
Mfg.
Inputs
Supplier
Perf.
Complaint
s
Tech Reqts
Rating
system
Suppliers Supplier
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Complaint
Processes
Outputs
Survey
Supplier
Evaluation
Customers
Ops Mgt
Rating
Buyers
system
Improved Engineering
Supplier
Perform.
Commit.
to
suppliers
Mfg.
Suppliers
62
SWOT Analysis
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Positive
Negative
Internal
Strengths
Weaknesses
External
Opportunities
Threats
63
Define Outputs
• Once completed, the Define Phase
should answer the following questions:
1)
2)
3)
4)
5)
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Who is the customer?
What matters?
What is the scope?
What defect am I trying to reduce?
What are the improvement targets?
64
Define Phase
Toll Gate Review
• Submit project storyboard to sponsor
• Toll Gate review presentation
• Sponsor provides feedback
• Project corrections are made prior to
proceeding to the next phase
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65
The Measure Phase
• Purpose
– To collect current performance of the
process identified in the Define phase
– This data is used to determine sources of
variation and serve as a benchmark to
validate improvements
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66
Measurements
• Benefits of having good data need to
outweigh the costs of getting it
• What does this measure do for the
Project?
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67
The Measure Phase
• Upon completion of the measure phase,
Project Teams will have:
» A plan for collecting data that specifies the type
of data needed and techniques for collecting
the data
» A validated measurement system that ensures
the accuracy and consistency of the data
collected
» A sufficient data set for problem analysis
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68
Measure - Key Concepts
• Measurement
• Variation
– Exists naturally in any process and is the reason
Six Sigma projects are undertaken
• Data
• Data Collection Plan
• Measurement System Analysis
– Ensures measurement techniques are reproducible
and repeatable
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69
Recording Measurements
• 3 stages
– The output stage
» These tell how well customer needs are being
met
– Parts of the process
» These are taken at critical points in the process
– The input stage
» These evaluate contributions to the process that
are turned into value for the customer
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70
Recording Measurements
• Output Stage
–
–
–
–
–
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Shortages
Line shutdowns
Quality – discrepant material
Material price variances
Internal customer survey
71
Recording Measurements
• Parts of the process
–
–
–
–
–
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Project milestones
Supplier ship on time performance
Supplier OTD
Supplier internal throughput yield
Supplier suggested cost reductions
72
Recording Measurements
• The input stage
–
–
–
–
–
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Supplier base size
% Buyers with degrees
% of spend covered by LTC’s
% of spend from reverse auction
Supplier FMEA’s
73
Operational Definitions
Walter Shewhart, the inventor of
statistical process control, believed
his work on operational definitions
to be of greater importance than his
work on control charts.
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74
Operational Definitions
“An operational definition is a
procedure agreed upon for
translation of a concept into
measurement of some kind.”
Deming, 1986
Operational definitions should be
valid and reliable.
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Operational Definitions?
Slump, I ain’t in no
slump. I just ain’t hitting.
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76
Operational Definitions
• On-Time Delivery
• On-Time Payment
• Late
• Defective
• Clean
• Good communication
• Engineering support
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Do you, your management, and your
suppliers agree on these definitions?
77
Determining Data Type
• What do we want to know?
• Review materials developed during
design phase
• What characteristics do we need to
learn more about?
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78
Data Collection Plan
• What data will be collected?
• Why is it needed?
• Who is responsible?
• How will it be collected?
• When will it be collected?
• Where will it be collected?
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79
Measurement System
Analysis
• After Data Collection Plan is complete,
it needs to be verified before actual data
is collected
• MSA is performed on a regular basis
• MSA ends when a high level of
confidence is reached that the data
collected accurately depicts the
variation in the process
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Analyze Phase
• The analyze phase allows the Project
Team to target improvement
opportunities by taking a closer look at
the data.
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81
Analyze Phase
• Capability Analysis - establishing current
performance level
• Graphical Analysis - a visual indication of
performance using graphs
• Root Cause Analysis – developing a
hypothesis about the causes of variation
• Root Cause Verification – verifying that the
planned action will generate the desired
improvement
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82
Process Capability
When selecting a process to perform an
operation, the inherent variability of
process output should be compared to
the range or tolerances allowed by the
designer’s specifications.
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83
Process Capability
process distribution
Lower
Specification
Upper
Specification
Much of the process output
fits within specification width
Almost all of the process output
fits within the specification width
In other words, is the
process capable of
producing the item
within
specifications?
A significant portion of the process output
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falls outside of the specification width
84
Analyze Phase
Cause Hypotheses
• Identifying Obvious Process Problems
–
–
–
–
–
–
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Disconnects
Process Map Review
Bottlenecks
Redundancies
Unnecessary distance
Rework
Decision points
85
Analyze Phase
Cause Hypotheses
• Quantifying Value-Added Steps
– Value-Adding
– Value-Enabling
– Non-Value-Adding
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Process Map Review
86
Analyze Phase
Cause Hypotheses
• Process Time Analysis
–
–
–
–
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Work time (value, but often only 5%)
Wait (& queue) time (usually dominates)
Setup time (tremendous leverage)
Move time (process dependent)
87
Analyze Phase
Tools
• Brainstorming . . . And beyond!
• Process Maps
• Cause-and-Effect Diagrams
• Focused Problem Statement
• Statistical Tools
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88
Cause-and-Effect Diagrams
Supplier Failure - Causes
Environment
Equipment
Business down
Strike
Lawsuit
People
Incapable equip
Flood
Earthquake
Fire
Business up
New employees
Tornado
Lack of PM
Process upset
Bad specs
Different standards
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Measurement
Processes
Strike
Fraud
Incompetence
Turnover
Illness
New source
Commodity allocation
Bankruptcy
Inaccurate PO
Materials
Mat'l price increase
89
Elements of Improve Phase






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Generate Improvement Alternatives
Create a “Should Be” Process Map
Conduct FMEA
Perform Cost/Benefit Analysis
Pilot
Validate Improvement
90
Improve Phase
Elements






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Generate Improvement Alternatives
Create a “Should Be” Process Map
Conduct FMEA
Perform Cost/Benefit Analysis
Pilot
Validate Improvement
91
Failure Modes Effects
Analysis
• Identify failure modes – How can this
product or process fail?
• Identify failure effects – What happens
when this failure occurs?
• Identify potential causes of the effects &
their probability of occurring.
• Rate the likelihood of detecting the
occurrence.
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FMEA - Output
• Ranked list of products that contribute
to risk
• List of actions and persons responsible
for addressing the risk
• Revised ranked priority list
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Improvement Phase
Methods
UCL
UCL
UCL
LCL
LCL
LCL
Process centered
Process not centered and in control
and not in control
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Evidence of additional
improvements
94
Review of Improvement
Phase
•
•
•
•
•
•
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Generate Improvement Alternatives
Create a “Should Be” Process Map
Conduct FMEA
Perform Cost/Benefit Analysis
Pilot
Validate Improvement
95
Generating Improvement
Alternatives



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Define Improvement Criteria
Generate Possible Improvements
Evaluate Improvements and Make
Best Choice
96
Pilot
Benefits of Pilot
• Determine best way to implement the
improvement
• Lowers risk of failure
• Increases opportunity for feedback
• Obtain buy-in from affected personnel
• Provides opportunity to revise the
improvement before full
implementation
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Stakeholder Analysis
People or Groups
Level of Commitment
Buy
Mfg
Eng
Enthusiastic Support
Help it work
Compliant
Hesitant
Indifferent
Uncooperative
Opposed
Hostile
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X
X
X
98
Review of Implementation
Phase
•
•
•
•
•
•
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Generate Improvement Alternatives
Create a “Should Be” Process Map
Conduct FMEA
Perform Cost/Benefit Analysis
Pilot
Validate Improvement
99
Control Phase
Why is it important?
• The Control Phase begins as the project
team tries to eliminate errors by
“Mistake Proofing” their improvement
alternative.
• Mistake Proofing attempts to eliminate
the opportunities for error.
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Control Phase
Why is it important?
• Mistake Proofing tries to make it
impossible for an operation to be
performed incorrectly, and/or correct
errors before they are passed to the next
worker, where they might become a
defect.
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Control Phase #2
• During the Control Phase the Project
team will:
1) Develop a plan to make sure the
measurement system will remain relevant
over the long term.
2) Establish Control Charts the process
owner will use to manage the process.
3) Create a Reaction Plan to address
situations that might cause the process to
move out of control.
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Control Phase #3
• The Control Phase ends when:
1) Standard Operating Procedures have been
updated.
2) Process Operators, the people who do the job,
have been trained for the new process.
• Once completed, the Control Phase should
sustain the gains the project made while
implementing ongoing process controls.
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Control Phase #4
• When is a project complete?
1) When other Black Belts can see the
ongoing controls work
2) When the customer sees the results
3) When the business sees the money.
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Six Sigma
Six Sigma People
• Executives
• Champions (deployment, project)
• Master Black Belts
• Black Belts
• Green Belts
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Control Phase
Methods
• During the Control Phase the Project
team will:
1) Develop a plan to make sure the
measurement system will remain relevant
over the long term.
2) Establish Control Charts the process
owner will use to manage the process.
3) Create a Control Plan to address
situations that might cause the process to
move out of control.
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Statistical Process Control (SPC)
• Chance variations are the many sources of
variation within a process that is in statistical
control. They behave like a constant system
of random chance causes.
• If only natural causes of variation are present,
the output of a process forms a distribution
that is stable over time and is predictable.
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Statistical Process Control (SPC)
• Assignable variation in a process can be
traced to a specific reason.
 Machine wear
 Misadjusted equipment
 Fatigued or untrained workers
• If assignable causes of variation are present,
the process output is not stable over time
and is not predictable.
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SPC - Assignable Causes
The operational definition of assignable
variation is variation that causes out-ofcontrol points on a control chart.
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Natural Patterns or Variations
Natural patterns exhibit the following characteristics:
• Most of the points are near the centerline.
• A few points spread out and approach the control limits.
• None (or only on rare occasions) of the points exceeds the
control limits.
Reference: Statistical Quality Control Handbook, Western Electric
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110
Unnatural Patterns or Variations
Unnatural patterns exhibit the following characteristics:
• Absence of points near the centerline produces a pattern
known as a “mixture.”
• Absence of points near the control limits produces an
unnatural pattern known as “stratification.”
• Presence of points outside of the control limits produces an
unnatural pattern known as “instability.”
Reference: Statistical Quality Control Handbook, Western Electric
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111
Tests for Unnatural Patterns
• Instability
– A single point falls outside of the 3 sigma control limits.
– Two out of three successive points fall in the outer one third of the
control limits.
– Four out of five successive points fall in the outer two thirds of the
control limits.
– Eight successive points fall on one side of the centerline.
• Systematic variable
– A long series of points are high, low, high, low without interruption.
Reference: Statistical Quality Control Handbook, Western Electric
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112
Statistical Process Control
Why use averages?
• To create a normal distribution
• Averages are more sensitive to change
than individuals
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113
Central Limit Theorem
Simulation
The distribution of
a sample
approaches
normal even
when the parent
population is not
normally
distributed.
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114
Control Phase
Mean and Range Charts
Process
Distribution
process mean drifting upward
UCL
Drift Detected
x-Chart
LCL
UCL
No drift detected
R-chart
LCL
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Control Phase
Mean and Range Charts
Process
Distribution
process variability increasing
UCL
x-Chart
No shift detected
LCL
UCL
Increase detected
R-chart
LCL
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Statistical Process Control
• Tolerance or specification limits
– Defined by an engineer
– Related to product design requirements
• Control limits
– Defined by the process
– Related to the variation in the process
– Unrelated to product needs
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117
Control Phase
Control Plans
• Structured approach for designing
value added control methods
• Control actions necessary to ensure
output quality
• May include controls anywhere in the
process
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118
Control Phase
Radar Chart
Product Features - s
F1
6
5
4
3
2
1
0
F5
F4
Days Late
F2
Cust-4
Cust-1
20
15
10
5
0
Cust-2
F3
Cust-3
Baseline
Current
Data Entry Errors
Jane
6
5
4
3
2
1
0
Jose
Baseline
Savings by Project
P1
Sally
P6
500000
400000
300000
200000
100000
0
P5
Steven
Current
P2
P3
Tom
P4
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Baseline
Current
Threshold
Actual
119
Control Phase
Radar Chart
S1
6
5
4
3
2
1
0
S6
Defect Levels by Supplier
S2
S5
S3
S4
Q1
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Q2
Q3
120
Final Toll Gate Review
• Submit project storyboard to sponsor
• Toll Gate review presentation
– Did the team carry out the agreed upon tasks?
– Did the team achieve the desired results?
• Sponsor provides feedback
• Project corrections are made prior to
termination or proceeding to next cycle
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121
Why TQM Fails
• Lack of Top Management Commitment
Commitment
Up Front
Appropriate
Training
• Wasted Education & Training
• Lack of Short-Term Results
Biz Case
Threshold
• Failure to Empower Employees
Charter
Brown, Hitchcock, and Willard - 1994
MTSU
122
Why Six Sigma Fails
(and it does)
• Lack of Top Management
Commitment
• Interdepartmental / crossfunctional issues
• Communication
• People
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123
Quality Tools
Kimball Bullington, Ph.D.
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124
References
Books:
•
•
•
•
•
•
•
Six Sigma Pocket Guide (Rath & Strong’s)
The Black Belt Memory Jogger (GOAL / QPC)
Six Sigma (Harry and Schroeder)
Implementing Six Sigma (Breyfogle)
The Six Sigma Way Team Fieldbook (Pande, et al)
The Vision of Six Sigma: A roadmap for breakthrough (Harry)
Why TQM Fails and What To Do About It (Brown, Hitchcock, &
Willard)
Web sites:
•
•
•
•
MTSU
www.isixsigma.com
www.ge.com/sixsigma
www.asq.org
www.aiag.org
125