Six Sigma

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Six Sigma
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Six Sigma Revolution

• Demings teaching about quality
• Quality initiatives
• SPC, Just-in-time, TQM
• Motorola in 1980s
• GE and AlliedSignal in 1990s
• Radical Changes in products and services
• Companies
• TI, ABB, DuPont, Ford, Dow Chemical, Johnson
  Controls, BASF, American Express, Nokia, Toshiba,

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What is Six Sigma?

• Vision
• Philosophy
• Company Strategy
• Method
• Culture
• Tool

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The Cost of Poor Quality (COPQ)
Warranty
Inspection
Tangible Quality Costs
Rework
Rejects
Scrap
Lost sales
Lost Opportunities
Late delivery
Hidden Factory
More Setups
Engineering change orders
Expediting costs
Lost Customer Loyalty
Excess inventory
Long cycle times
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The Nature of the Process
On-target,
less variation
Variation
Off-Target
Six Sigma goal identifies and controls process
variations and targets.
Six Sigma methodology identifies processes that
are off-target,
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What is Six Sigma?

• Integrates
• Customer focus
• Breakthrough improvement
• Continuous improvement
• People Involvement
• Defines goals and performance metrics that yield
  clear and measurable business results.
• Applies statistical tools to achieve breakthrough
  financial gains

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Six Sigma Focus

• Meeting customer needs
• Rapid breakthrough improvement
• Process capability and improvement
• Positive and deep culture change
• Real financial results that impact the bottom
  line

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Structure / Roles
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Building the 6? Team

• Executive Management
• Set meaningful goals and propel implementation of
  six sigma in the organization
• Champion
• Create general scope and set strategic direction
  of the projects and teams
• Drive project success by removing obstacles and
  allocating sufficient resources
• Master Black Belt
• Consults, trains and mentors the local
  organization on Six Sigma
• Black Belt
• Delivers successful projects (high corporate
  gains) using the Breakthrough Strategy
• Green Belt
• Delivers local projects (lower monetary gains)
  using the Breakthrough Strategy
• Other key members
• Process Owner maintains system improvements at
  project completion
• Process Sponsor provides resources, time, money
  and direction of your project
• Financial Analyst verifies the financial gains
  of the project
• Team members implement the steps for six sigma
  success

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What is Sigma?

• s (sigma) - A Greek letter
• In statistics - the standard deviation from the
  average/mean
• Assumption of Gaussian/Normal distribution
• Six Sigma Methodology uses s to define the
  capability of a process
• As the standard deviation of your process
  decreases, the sigma level of your process
  increases.

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Normal/Gaussian Distribution
34.13
34.13
13.06
13.06
2.14
2.14
0.13
0.13
-3s -2s -1s m 1s
2s 3s
68.26
95.46
99.73
68.26 of the population is within /- 1
of the
??
?
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Process Capability

• 6s process is to get acceptable results through
• Identification of variations
• Quantification of variations
• Elimination/control of variations

USL
LSL
Defects
Defects
Acceptable
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Six Sigma - Goal
s
Defects per Million Opp.
1
691,462
308,537
2
66,807
3
6,210
4
233
5
3.4
6
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Six Sigma -- Practical Meaning
99.99966 Good (6 Sigma)
99 Good (3.8 Sigma)
16,000 lost articles of mail per hour
5.4 articles lost per hour
22,000 checks deducted from the wrong bank
account each hour
7.5 checks deducted from the wrong bank account
each hour
500 incorrect surgical operations per week
1.7 incorrect operations per week
2 unsafe plane landings per day at OHare
International Airport in Chicago
1 unsafe plane landing every four years
50 newborn babies dropped at birth by doctors
each day
1 newborn baby dropped at birth by doctors every
2 months
Source Six Sigma Revolution, George Eckes
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Overall Approach
Define
Define Problem
Measure
Practical Problem
Analyze
Statistical Problem
Statistical Solution
Improve
Control
Practical Solution
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The Strategy
USL
LSL

• Characterize
• Optimize
• Breakthrough

T
USL
LSL
T
USL
LSL
T
USL
LSL
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The 6 Sigma Breakthrough Method

1. Define project and scope
2. Establish process

D
Define

1. Identify key input/outputs variables
2. Identify process capability/ measurement system

M
Characterization
Measure
5 Establish Product Capability 6 Identify
Variation Sources
A
Analyze
7 Screen Potential Causes 8 Verify Variable
Relationships
I
Improve
Optimization
9 Validate Measurement System 10 Implement
Process Controls
C
Control
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Defining the Process

• Team members who understand the process
• Put together a flow of the process
• An common foundation for team activity
• Identification of outputs for measurement and
  capability studies
• Estimates of sigma levels at each step

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Project Scope

• Problem statement
• Goals/objectives for the team
• Measurable gains (monetary terms)
• Milestone
• Customer needs and requirements

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Process Mapping

• What is process mapping?
• Graphical depiction of the ACTUAL process
• What will the tool identify?
• All value added and non-value added process steps
• Process inputs (Xs)
• Process or product outputs (Ys)
• Data collection points

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Basic Flowchart Symbols
Activity
Start / Stop
Flow Line
Decision Point
A
A
Connector
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Basic Structure

• What are the steps to capture?
• What are the operational steps?
• What are the decision points?
• Where are the problem area?

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Versions of a Process
What You Think It Is...
What It Actually Is...
What You Would Like It To Be...
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Preparing the Process Flowchart

• Team Effort
• Engineers
• Line Operators
• Line Supervisors
• Maintenance Technicians
• Inputs to Flowcharts
• Brainstorming
• Operator Manuals (SOPs, AOPs, etc.)
• Engineering Specifications
• Operator Experience
• 5Ms and an E (Fishbone)
• Machine (Equipment), Method (Procedures),
  Measurement, Materials, Manpower (People),
  Environment

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Measurement Phase

• The input/output variables
• The capability of the process
• The defects in the process
• Sigma level

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Purpose of Measurement Phase

• Identify and define defects
• Identify key input variables (Xs) and key output
  variables (Ys)
• Document the existing process
• Establish a data collection system for your Xs
  and Ys if one does not exist
• Evaluate measurement system for each key output
  variable using CE, FMEA, etc.

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The Importance of Defects

• Since Six-Sigma focuses on reducing defects, it
  is necessary that each project definition clearly
  specifies the defect(s) that will be reduced

• Count the number of times the letter f appears
  in the following statement

Six Sigma Revolution, George Eckes, pg 2
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A simple test
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• What was your answer?

The final information are the results of years of
scientific studies and were often combined with
years of experience. We must often configure
the files for the final report during the
conference.
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What Causes Defects?

• Variation due to
• Manufacturing processes
• Supplier (incoming) material variation
• Unreasonably tight specifications (beyond
  customer needs)
• Unstable Parts and Materials
• Inadequate training
• Inadequate Design Margin
• Insufficient Process Capability

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How Do We Improve Capability

• Understand that the Outputs (Ys) are determined
  by Inputs (Xs).
• If we know enough about our Xs we can accurately
  predict Y without having to measure it.
• If we dont know much about our Xs, then we have
  to resort to inspection and test.
• If can control the Xs, then we reduce the
  variability in Y, which decreases defects, and
  possibly, eliminates/reduces inspection and test.

Y F (x1, x2, x3,xn)
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Data Collection Plan
What to measure Type of measurement Type of Data Operational Definition Data Collection Form(s) Sampling Baseline Six Sigma


Six Sigma Revolution, George Eckes, pg 72
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Data Collection Data

• Type of Data
• Discrete
• Continuous
• Sampling
• Representative
• Random Sampling

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Metrics What to measure?

• Defects per million opportunities (DPMO) drives
  plant-wide improvement
• Sigma level allows for benchmarking within and
  across companies

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Calculating Sigma-Level

• Sigma level
• units item produced or being serviced
• defect event that does not meet the
  customers requirement
• opportunity chance for a defect to occur

• Calculate Defects per Million Opportunities
  (DPMO)

Total
defects x 1,000,000
DPMO

( of Opportunities for Error) x ( of units)

• Go to a Sigma Chart and Estimate the Sigma Level

Six Sigma Revolution, George Eckes, pg 99
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DPMO and Sigma Level
DPMO Sigma Level DPMO Sigma Level
       
1000000 -3.4 158655 2.5
999997 -3.0 66807 3.0
999968 -2.5 22750 3.5
999767 -2.0 6210 4.0
998650 -1.5 1350 4.5
993790 -1.0 233 5.0
977250 -0.5 32 5.5
933193 0.0 3.40 6.0
841345 0.5 0.29 6.5
691462 1.0 0.02 7.0
500000 1.5 0.00 7.5
308538 2.0 0.00 8.0
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Tracking Trends in Metrics
Our objective is to track the trends in the
Metrics to establish, based on fact, our
improvements. These metrics can be productivity,
defects, time, yield, etc.
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Purpose of the Analysis Phase

• Establish baseline capability for key output
  variables (potential and overall)
• Examine both the process and data for analysis
• Determine and validate the root causation of
  project problem
• To reduce the number of process input variables
  (xs) to a manageable number
• To determine the presence of and potential
  elimination of uncontrolled variables

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Three Sigma Process
Centered
1.5 Sigma Shift
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Three Sigma Process
Centered
1.5 Sigma Shift
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Six Sigma Process
Centered
1.5 Sigma Shift
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Analysis Tools
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Purpose of the Improvement Phase

• Key variables are identified and validated during
  this process .
• Look to eliminate, reduce or neutralize the
  effects of the input or root cause.
• Design experiments to manipulate the key input
  variables (Xs) to determine their effect on the
  outputs (Ys).
• Select the solution that impacts the root cause
  the most.

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Design of Experiment

• Full Factorials
• 2K Factorials
• Fractional Factorials

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DOE Example

• Objective To reduce consistency variation in Y
• Output Variation (Lower is Better)
• Full Factorial Inputs
• RPM (Lo, Hi)
• Speed (Lo, Hi)
• Time (Lo, Hi)

Main Effects Plot
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14
12
10
8
Speed
Time
R
P
M
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Purpose of the Control Phase

• Develop and implement long-term control methods
  to sustain the gains identified
• Document the control plan with specific roles
  identified
• Monitor long-term delivered capability and
  performance
• Verify benefits and cost savings

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Control Tools
Control

• Control Plan
• SPC
• Mistake Proofing
• Automated Control

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Dynamics of Execution Strategy
40 - 50 Inputs
Process Map/CE
15 - 20 Xs
M
Capability/Multi-Vari
8 - 10 Xs
A
DOE
I
3-5 Critical Xs
Control Plan
C
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Who needs Six Sigma?
As long as there is a process that produces an
output, we can apply the Six Sigma Methodology.
Every function has a customer and a deliverable.
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Six Sigma Project Consideration

• Project is supportive of corporate objectives
• Project is focused on an ongoing process /
  recurring events that is causing defects
• A 70 reduction in defects results
• Customer (internal or external) will see or feel
  the result
• Takes 4-6 months to complete
• Little or no capital required

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Possible Six Sigma Projects

• Low yield rate
• High operating costs
• High customer failure/complaints
• High scrap/rework
• High inventory/WIP
• High maintenance costs
• Supplier product quality problems
• Low productivity
• Long cycle times
• Low machine utilization

• Inaccurate information
• Missing information
• Poor process control
• Frequent set up requirements
• Long set up time
• Unpredictable product performance

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Six Sigma Success
Visible top-down leadership and commitment
Education and training
Recognize and focus on customer needs
World-class quality
Establishing meaningful, focused metrics
DMAIC - Define, Measure, Analyze, Improve
Control
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Credits

• This module is intended as a supplement to design
  classes in mechanical engineering. It was
  developed at The Ohio State University under the
  NSF sponsored Gateway Coalition (grant
  EEC-9109794). Contributing members include
• Gary Kinzel. Project supervisors
• Phuong Pham.. ... Primary authors
• L. Pham ... Audio voice

Reference Six Sigma Revolution, George Eckes,
John Wiley Sons, Inc., New York, 2001.
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Disclaimer

• This information is provided as is for
  general educational purposes it can change over
  time and should be interpreted with regards to
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  State University and Gateway do not guarantee the
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