Six Sigma
Dr. Ron Lembke
SCM 462
DMAIC
SELECTION CONSIDERATIONS
Financial return
Impact on customers and organizational effectiveness
Probability of success
Impact on employees
Fit to strategy and competitive advantage
SELECTING PROJECTS
Conformance Projects
Unstructured Performance Projects
Problems because system poorly specified
Efficiency Projects
Acceptable products, not meeting internal goals
Product Design
Not meeting customer CTQ
Process design
DMAIC
Define
Measure
Analyze
Improve
Control
(Alternate meaning: Dumb Managers Always Ignore
Customers)
DEFINE
Charter / rationale for the project
Why this, not others, need for project, costs, benefits
Developing a project charter (statement of the project)
Scoping:
Improve motor reliability
Most problems from brush wear
Problem with brush hardness
Reduce variability of brush hardness
DEFINE
Gather voice of the customer data to identify critical-to-quality (CTQ) characteristics important to customers
Select performance metrics
What are current levels
Expected improvements
What will need to be done, by whom
DEFINE
SIPOC Understand the relationships between
Suppliers
Inputs
Process
Outputs
Customers
MEASURE
Develop operational definitions for each CTQ characteristic
Figure out how to measure internal processes affecting each
CTQ, KPOV (Key process output variables), KPIV (Input Vars)
Y = F(x)
Figure out what data we need to collect
Easy to collect correctly
Interrupt process as little as possible
Collectors understand why collecting
“gage study” to determine the validity (repeatability and reproducibility) of the measurement procedure for each CTQ
Baseline data
Collect baseline capabilities for each CTQ
Determine the process capability for each CTQ
Y=F(X)
CHECKSHEET
Consider all possibilities
Be clear – no guessing, training?
You might have forgotten some
Might need to revise – some cover too many things
Learn about different cases
PARETO CHART
3. Collect the data
5. Tabulate the data – Do as %, if you want to
(6. Put each problem into dollars of cost, most complaints, lost employee minutes, etc.)
8. Sort biggest to smallest, graph.
Analyze – p. 87 – what would you fix?
PARETO CHART
Further study of major categories
Grouping together smaller ones
Look for common causes
ANALYZE
Understand why defects and variation occur
Find the root causes
5W = 1H
Identify key causes
Experiments to verify impact
Formulate hypothesis, collect data
ANALYZE
Does the process work the way we think it does?
Identify upstream variables (x’s) for each CTQ
Process mapping
Operationally define each x
Collect baseline data for each x
Perform studies to determine the validity (repeatability and reproducibility) of the measurement process for each x
Establish baseline capabilities for each x
Understand the effect of each x on each CTQ
IMPROVE
Brainstorm ideas of potential root causes– everyone participates
Generate ideas about potential root causes
Understanding the process, not solving the problem yet
CAUSE AND EFFECT DIAGRAM
Ishikawa, Fishbone
Puts things in an organized way
Separate things into manageable parts (like KJ in that way)
Methods, Materials, Machines, People,
Environment, Information
Create the diagram
Analyze the diagram – look for cost effective solutions!
WHY-WHY
Ask “why” 5 times, or as many as it takes
List of next steps, things to investigate
GRAPHS
Scatter plots - Look for trends
Run charts – same thing
DJIA = Financial Performance?
IMPROVE
Determine optimal levels of critical x’s to optimize the spread, shape and center of the CTQ’s
Action plans to implement the optimal level of the x’s
Conduct pilot test of the revised process
RUN INTO RESISTANCE?
Force Field!
FORCE FIELD
ANALYSIS
For and against
Action items for each
Strength of each
CONTROL
Risk abatement planning and mistake-proofing to avoid potential problems with the revised settings of the x’s
Standardize successful process revisions in training manuals
Control revised settings of the critical x’s
Turn revised process over to the process owner for continuous improvement using the PDSA cycle
REPORT PHASE
Tell everyone what you did, so they can learn from it
HW – P. 97
Questions 3, 4, 6, 7, 10, 16
