Lean Six Sigma DMAIC Workshop Green Belt Part 6
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Transcript of Lean Six Sigma DMAIC Workshop Green Belt Part 6
Lean Six Sigma DMAIC WorkshopGreen Belt Part 6
6 σ Green Belt
04/20/23 1Green Belt Training
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Control
Control
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Control Process Flow
Develop Control strategy
Develop control
plan
Update SOP’s and training plans
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Key Concepts
Prevention vs detection
Visual Factory
Control Plan
Reaction Plan
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Control Phase
Control is a means of sustaining improvements by eliminating the opportunity for defects to occur, or monitoring the process using a feedback system
Sustaining the gains is key!
We move from detection of defects to prevention of defects
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Error Proofing
The avoidance of an error before it occurs
Error-proofed processes are designed to require extensive operator training while allowing the operation to be performed the correct way EVERY time.
Automation
Fixtures
Jigs
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Visual Factory
Visual Displays
Communicate important information, but do not what people or machines do
Visual Controls
Communicate information and/or build controls into the process so that activities are performed according to standards
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Control Charts
Control Charts
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Variation
Variation means that a process does not produce exactly the same result every time the product or service is delivered
Variation exists in all processes
Measuring and understanding variation in our business processes helps identify specifically what the current level of performance is and what needs to change in order to reduce the variability and therefore reduce the defects delivered to customers
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What Causes Variation?
SuppliersProcess Inputs
Business Processes
Process Outputs
Critical Customer
Requirement
Defects
Variation in the output of processes causes defects
Root cause analysis of variation leads to permanent defect
reduction
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Control Charts - Basics
Control Charts
Have the ability to indicate the presence of special causes that upset our processes
Help us to detect, diagnose, and correct production problems in a timely fashion
Provide an easy to understand visual indicator of process performance
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Control Charts - Basics
Steps to building an appropriate control chart
1. Determine the type of data
2. Collect data consistently
3. Select the appropriate control chart
4. Build the control chart
5. Analyze process performance
6. Take corrective action
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Common Cause Variation
There are always inherent chance causes responsible for natural variation in all processes due to “normal” variation in materials, environments, methods, etc. (common cause)
Variation within a stable pattern is inevitable
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Special Cause Variation
Once we have an indication of a shift outside a stable pattern of variation, we must discover the reason for the shift (special cause)
We want to remove the influence of a special cause if it is adversely affecting product-process quality
If the special cause influence is improving product-process quality (e.g., 6 Sigma projects), we want to permanently capture its effect
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Eliminate Special Causes
In Control Variation Out of Control Variation
Days Time
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Issues on Control Charts
It is critical to understand that:
Control charts do not tell us whether or not we are meeting tolerance specifications consistently
They neither explicitly identify nor remove special causes
Control charts are statistical based devices for addressing process stability
We need to develop meaningful process logs to account for and document physical characteristics, action items, and results obtained
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Charting Variation – Control Charts
Days
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Benefits of a Well-Defined Control Plan
Improves overall quality by reducing chances of deviation
Reduces defects by keeping processes centered
Aid in timely troubleshooting of the process
Serve as a communication tool for changes in CCR‘s
Sustain improvements
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Control Plan Contents
Characteristic/Parameter
CCR
Specification/Requirement
Measurement Method
Sample Size
Frequency
Who measures
Where recorded
Decision Rule/Corrective Action
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Reaction Plan
Actions to be taken when an out of control condition occurs
When do we react?
Who needs to be involved?
What other information do we need to have?
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Procedures and Standards
Procedures and standards are the details behind the activities documented on the business process map
They serve as a vehicle for every employee -from senior executives to hourly workers -to gain an understanding of the improvement
Procedures are both a training aid and a means to ensure successful implementation
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Procedures and Standards
Contents They should be at such a level that the job can be
performed well by employees who are not fully trained They should be specific. Tell precisely what actions to
take and when and where to take them. Make it clear where people‘s responsibilities lie
They should describe how to prevent product and service variation
They must be able to be followed. No contradictory or unrealistic instructions.
Priorities must be considered. Focus on the root causes
Formats– Procedures – Checklists– Flowcharts – Metrics
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Communication Planning
Research has shown that one of the most significant variables in successful implementation is the quality of communications supporting a change. Teams must be very careful to develop the right communications for the right people and deliver them at the right time
Channels: There are numerous communication channels such as:
One-on-one meetings Electronic mail Posters Bulletin boards Small discussion groups or workshops Videos Teleconferencing or video teleconferencing Memorandums or personalized letters Voice mail
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Presentation Checklist
Do your research and preparation:
Understand audience
Include stakeholders
Anticipate questions
Presentation Opening:
Set the expectations
Share the burning platform
Establish a sense of urgency
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Presentation Checklist
Deliver Body:
Present “As Is” and “To Be”
Use facts and data
Show how stages of DMAIC tools were used
Sell Your Solution:
Be Specific
Provide Examples to prove point
Link Benefit/results to actions
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Presentation Checklist
Closing:
Make recommendations
Include How-By
Present resource requirements
Ask for approval
Follow-up:
Post presentation debrief
Publish meeting minutes
Thank participants
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Appendix
Appendix
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Statistical Tools Summary
Tool What Type of Data When to Use How to Apply this Tool in my
Work
Histogram Visual display of one variableshowing data center, spread,shape and outliers
Continuous ordiscrete
1. Summarize large amounts of data2. To get a “feel for the data‟3. To compare actual description tocustomer specs
MultivariCharts
Bar chart comparison of subgroupson one variable.
Continuous ordiscrete
To visually compare sub-groups byindividual data points and the mean.In MINITAB 12 only. To identifymajor source of variation.
Box Plots Visual display of thesummary of Y data groupedby category of X
Y=continuousX=discrete orcategorical
Summary display to visualizedifferences in data center, spread andshape across categories.
Run Charts
Plots observation in timesequence
Y=continuous ordiscrete
To view process performance overtime for trends, shifts or cycles.
Control Charts
Plots observations in timesequence against a mean andcontrol limits
Y=continuous ordiscrete
To monitor the process in order tocontrol and improve processperformance over time for trends,shifts or cycles. To identify specialcauses.
ScatterDiagram (Plot)
Plots a response Y versus apredictor X
Y=continuousX=continuous
To understand the possiblerelationships between two variables.To identify possible root causeswhich are related to Y. Do not usewith special causes.
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Statistical Tools Summary
Tool What Type of Data When to Use How to Apply this Tool in my
Work
Behaviorally Anchored Scales
A response scale on which specific points are named or described to clarify the differences between points.
Discrete / Categorical: Nominal(name)Ordinal(order)Continuous: Interval
To translate subjective or qualitative issues into data (discrete or continuous). To reduce variation in the response measured.
t-Test Determine if there is a difference between two groups.
Y=continuous X=discrete or categorical
1. Test if sample average = specified value
2. Test if 2 sample means are equal
3. Paired t: to reduce variation when comparing two sample averages Analysis
Analysis of Variance
Determine if there is a difference among many groups.
Y=continuous X=discrete or categorical(2 or more Xs)
Determine of there is a statistically significant difference among the groups.
Discrete Data: Chi Square Determine
Determine if there is a difference for observed frequencies of 2 discrete variables.
Y=discrete or categorical X=discrete or categorical
Determine if there are relationships between two discrete variables.
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Statistical Tools Summary
Tool What Type of Data When to Use How to Apply this Tool in my
Work
Regression(Linear &Multiple)
Summarizes, describes, predicts and quantifies relationships.
Y=continuous X=continuous or discrete
1. Determine if there is evidence of a relationship between Xs and Ys.
2. Model data to develop a mathematical equation to quantify the relationship.
3. Identify root causes.4. Make predictions using the
model.
Logistic Regression
Summarizes, describes, predicts and quantifies relationships.
Y=discrete X=continuous or discrete
1. Determine if there is evidence of a relationship between Xs and Ys.
2. Model data to develop a mathematical equation to quantify the relationship.
3. Identify root causes.4. Make predictions using the
model.
Design of Experiments(DOE)
Systematic and efficient proactive approach to testing relationships.
Y=continuous or discrete X=continuous or discrete
To establish cause and effect relationship between Ys and Xs. To identify “vital few” Xs.
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Control
Websites:
•www.isixsigma.com
•www.asq.org/sixsigma/
•www.minitab.com/