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Doug Hlavacek, EcolabSTAT Past Chair
October 10, 2008
Statistical Thinking: Past, Present and Future -
2008 Fall Technical ConferenceASQ Statistics Division Invited Session
Agenda• Introduction
– Doug Hlavacek, Ecolab• Statistical Thinking - Past
– Roger Hoerl, GE CRD• Statistical Thinking - Present
– Gordon Clark, Ohio State University• Statistical Thinking - Transition
– Robert Mitchell, 3M LSSQ• Statistical Thinking - One Future
– Roger Hoerl, GE CRD• Panel Discussion
Statistical Thinking
Statistical Thinking is a philosophy of learning and action based on the following fundamental principles:
All work occurs in a system of interconnected processes,
Variation exists in all processes, and
Understanding and reducing variation are keys to success.
Glossary and Tables for Statistical Quality Control -Quality Press, 1996
Statistical Thinking
• Emphasizes critical thinking• Different from statistical tools...
Not number crunching
QuestionsThe Statistics Division first published the official definition of Statistical Thinking in the 1996 edition of the Glossary & Tables for Statistical Quality Control.
Statistical Thinking is a philosophy of learning and action based on the following fundamental principles: • All work occurs in a system of interconnected processes, • Variation exists in all processes, and • Understanding and reducing variation are keys to success.
Three past chairs of the Statistics Division (Roger Hoerl, Gordon Clark, and Bob Mitchell) will share their perspectives about the past, current, and future of Statistical Thinking. What question(s) about Statistical Thinking do you have for the panelists?
Roger Hoerl, GE Global Research
Statistical Thinking:The Past
W. Edwards Deming• To the best of my knowledge, never used the
term “Statistical Thinking”• Taught that statistical concepts apply to
management, or anything else– e.g., the “red bead” exercise– Focused on understanding, not the formulas
• Gradually made the case that we were missing something beyond statistical methods per se– But didn’t articulate it well, in my opinion
• The statistical community continued to focus on the math
Ron Snee• More than anyone else, broadly popularized and
disseminated the concepts of statistical thinking• Defined statistical thinking in 1986 as “thought
processes”, not formulas• Clarified the distinction (synergy) between
statistical thinking and methods• Later published introductory business statistics
text based on statistical thinking (2002)– Statistical Thinking: Improving Business Performance
• The statistical community continued to focus on the math
Heero Hacquebord
• Afrikaner student of Deming’s• Taught public “Statistical Thinking” courses
beginning in 1987– Was more articulate than Deming, in my opinion
• Emphasized managerial implications of the concepts– e.g., the hazards of “managing by the last data point”
• The statistical community continued to focus on the math
Quote From Tom Pohlen, 3M• Attended Hacquebord’s course in 1988• “I went into the course thinking that I already knew
everything I needed to know about SPC. I came out of the course with a whole new perspective on statistics, looking upon SPC and other statistical applications more as a way of thinking about processes so we can learn how to improve them. I also found that I could never again be satisfied with looking at numbers without graphical analysis.”
• Pohlen clearly had a “Damascus road” experience• The Statistical community continued to focus on the
math
Statistics Division Statistical Thinking Tactical Planning Team
• Chartered at a Statistics Division long-term planning meeting in 1994– Developed “5 year plan”
• Published formal definition in 1996 Glossary and Tables for Statistical Quality Control - a seminal event!
• Wrote a Special Publication on Statistical Thinking for division members in 1996
• Wrote booklet: “Improving Performance Through Statistical Thinking” (Quality Press, 2000)
• Organized several conference sessions to “get out the word”
• The statistical community continued to focus on the math
Impact of These Efforts
• Statistical thinking became part of the vocabulary of statistically-oriented quality professionals– Among this group, there is a realization of the
uniqueness of statistical thinking versus statistical methods
• While not always recognized, statistical thinking principles became a cornerstone of major improvement initiatives, such as TQM and Six Sigma
Gordon ClarkThe Ohio State University
October 10, 2008
Statistical Thinking: Process Improvement Strategy
GMC1
Illustration of ProcessImprovement Strategy
• Understand the Process– Ricoh’s Numazu plant
produced raw materials for paper copier toner
• Resin• Consistent quality &
volume
Collect data on key input, process and output measures
OutputlTheoreticaOutputActualYield = Why is Yield above 100%?
Analyze Process Stability
Special Cause?
• Mechanical problem was special cause– Fixed
Evaluate Process Capability
• Investigated customer needs for batch output quantity– 4300 kg ± 5 kg
Analyze Common-Cause Variation
Study Cause & Effect Relationships
• Extraction of 2nd phase volume– Resin remained in tank after dividing phase– Line B had less material than line A– Changed dividing procedure
• Data showed no detectable difference between batch sizes
• Implement change– Variation in output quantity reduced but still
too large
Solvent Feed Ratio Potential Cause
• No relationship should exist
• Ratio measurement affected by time solvent sat in tank
• Change implemented • Output relationship with feed ratio disappeared• Variation still too high
Weighing Process Potential Cause
• Found problems affecting weighing process accuracy– In-process (manual)– Final (automatic)
• Problems corrected• Change implemented
– Output variation met tolerance
Output Control Charts
ST or Hoerl-Snee Process Improvement Strategy
• References– Hoerl, R. W. and R. D. Snee (1995). Redesigning
the Introductory Statistics Course. Madison, Wisconsin, University of Wisconsin, Center for Quality and Productivity Improvement.
– Britz, G. C., D. W. Emerling, et al. (2000). Improving Performance Through Statistical Thinking. Milwaukee, WI, ASQ Quality Press.
– Hoerl, R. and R. D. Snee (2002). Statistical Thinking - Improving Business Performance. Pacific Grove, CA, Duxburry
– Blog: http://www4.asq.org/blogs/statistics
Process Improvement
Strategy
Comparison with DMAIC Strategy
• Improvement occurs in iterative sequential steps– Enhanced PDCA approach to improvement
• Emphasis on removing special-cause variation first– Analysis of special cause variation differs
from common-cause variation
Current Scope of SQC
Douglas Montgomery (2005). Introduction to Statistical Quality Control, Fifth Edition
– “Quality is inversely proportional to variability”– “Quality improvement is the reduction of variability in
processes and products”– “quality improvement … three major areas..statistical
process control, design of experiments, …acceptance sampling.”
Observation• Lacks an overall process improvement strategy
Statistical Process Control
Montgomery (2005)– “Statistical Process Control (SPC) is a powerful
collection of problem-solving tools useful in achieving process stability and improving capability through the reduction of variability”
Observations• Lacks an overall process improvement strategy• In practice, focus is on control charts• More emphasis needed on reducing common-cause
variation
Statistical Process Improvement
• Upgrade to SQC and SPC• Use Statistical Thinking• Use Hoerl-Snee Process Improvement
Strategy
Robert Mitchell - 3M LSSQOctober 10, 2008
Statistical Thinking: The Transition to Entitlement Quality
Quality Journey
• A typical exampleSix Sigma
– Lean– Innovation
– Human Sigma-- Entitlement Quality
DMAIC• Project-by-Project Improvement• Eliminate defects (nonconformance)• Business Critical Y: Cost, Cash, Growth• Project length: 6-9 months• Tools focused• Metrics: Primary, Secondary, Counterbalance
Learnings:– Internally-focused. Where is the customer?– Lack of systems thinking... Sub-optimization– Must focus on building process capability
Lean
• Eliminate waste (8 forms of muda)• Eliminate non value-added activities• Improve flow, Reduce cycle-time• Tools focused... Not a philosophy, like TPS• Metrics: Yield, Time, Productivity, Inventory
Learnings:– Cannot reliably improve flow unless process is stable– Lack of knowledge of variation– Cultural norms and behaviors (LMS) must be created
Commercialization
• Collect and translate fuzzy VOC• Understand variation in markets and customer
segments• DFSS tools to design and deliver value-added
products and services
Idea Concept Feasibility Dev’t Scale Up Launch Post-Launch
NPI Framework
Learnings:– Commercialization is a business strategy– Innovation is messy, not linear– ST concepts drive robust product design
Process Approach
SuppliersInputs
ProcessOutputs
Customers
A series of activities that converts inputs into outputs
The business should see the improvement ($), the customer should “feel” the improvement
ST in All Improvement Initiatives
Developprocess
knowledge
All workis a process
Processesare variable
Analyzeprocessvariation
ChangeProcess
ReduceVariation
ControlProcess
ImprovedQuality
Satisfied:• Employees• Customers• Shareholders• Community
Roger Hoerl, Ron Snee, Statistical Thinking -Improving Business Performance, pg 13(ISBN 0-534-38158-8)
Human SigmaJohn H. FlemingGallup Consulting
• An holistic approach to optimizing the vital signs of a company’s human systems
• Focus on reducing variability in performance and improve organizational effectiveness– The human aspects that drive profitability and growth
• In a service economy, value is created when an employee meets and interacts with the customer
• Variation = Danger
3M Entitlement Quality
• Improvement methodologies are often treated as “floats in a parade” (Jim Buckman, JuranCenter, U of MN Carlson School).
• But the improvement principles and tools are bedrock... building blocks to continual improvement.
• EQ integrates Statistical Thinking into a system of continuous improvement approaches of Quality-Lean-Six Sigma-Innovation methods to optimize customer value.
3M Entitlement QualityBack to basics...
– Focus on key business processes, value streams, and customer CTQs
– Characterize process behavior (average and variation, structure)
• “Plot the dots... and look at the plots” (Lynne Hare)
– Assess process state and capability
– Apply a critical thought process
– Address the root causes using the appropriate tool regardless of the improvement toolkit.
3M Leadership AttributesBuilding the Culture
• Thinks from the Outside In• Drives Innovation and Growth• Develops, Teaches and Engages Others• Make Courageous Decisions• Leads with Energy, Passion and Urgency• Lives 3M Values
Roger Hoerl, GE Global Research
Statistical Thinking: The Future
Statistical Thinking – What Next?• There will always be “the next big thing” in
the business world– Total Quality Management– Reengineering– Six Sigma– Lean– Innovation– ???
Statistical Thinking – What Next?• However, some things never go out of style:
– Chocolate– High heels– Diamond rings– Pizza and beer– Spending holidays with the family
• Business improvement, including the use of statistical thinking, is one of those things– The concepts are timeless, and they work!
One Specific Thought• The first principle of the Statistical Thinking
definition:– “All work occurs in a system of interconnected
processes”• This critical principle has not yet been applied
broadly to continuous improvement initiatives– We have tended to focus on one improvement
process: Six Sigma, Lean, Reengineering, etc.– We need initiatives that emphasize the system of
interconnected improvement processes
A System of Interconnected Improvement Processes*
ProcessPerformance
Data
Reports &Information toManagement
Feedback Feedback
ProcessImprovements
ImprovementProjects
ContinuousImprovement
System
ProcessControl
PeriodicAnalysis and
Reviews
Customers
The Process
Product &Process
Redesign
Whe
n N
eede
d
*From Snee and HoerlLeading Six Sigma (2003)
Feedback
System of Improvement Processes• Must be managed and optimized as a system
– Not sub-optimized at the process level– No competition among “favorite methods”
• Covers “Juran Trilogy”:– Design, improvement, control – Long-term, medium-term, short-term
improvement• Avoids the “fad of the month” trap• “Back to the future” – an idea whose time has
come (again)