Lean has traditionally focused on cycle time reduction, inventory reduction, reduction of floor space, by the elimination of the 7 hidden wastes. Six Sigma has traditionally focuses on variance reduction (the elimination of “noise factors”) to improve quality. The goal of both is to produce a financial benefit.
This graphic summarizes the tools have been traditionally used for Cycle Time Reduction (Lean) and for Variance Reduction / Quality Improvement (Six Sigma) and which ones are common to both.
The point of this table is to illustrate that a process can be improved by reducing steps (Lean) and-or increasing quality (Six Sigma) of each step. For example, a 10 step process with a 3 sigma quality level will only produce products with a 50% yield (the probability that a good part will be produced each time a new one is started through the process). The combination of Lean and Six Sigma provides the best possible result. It is suggested that steps be eliminated before efforts are made to improve quality of each step.
The first step in process improvement is to gain process knowledge. Without this step we can stumble. True understanding of our processes is a competitive advantage.
Major process improvement can be made with the basic quality and statistical tools. Only after the process is operating at high performance do we need to employ more sophisticated knowledge gaining tools.
The look backs performed at 12-months have repeatedly demonstrated that improvements are sustained. The improvements are typically made by changes in procedures. The only money spent on Lean Sigma projects is typically for collecting data. The investment is the time the team takes to understand the process, collect and analyze the data, and implement the changes.
Variance Reduction International, Inc. Lean Six Sigma VarianceReduction.com (909) 484-2950
Lean Sigma Process Improvement Cycle UCL LCL Avg BUSINESS UNIT SCORECARD VOICE OF CUSTOMER Gap Identified STRATEGIC PLAN BUSINESS OBJECTIVES BUSINESS MEASURES VALUE STREAM PROCESS FLOW PROCESS MEASURES PROCESS SCORECARD Y's X's Improve Control Define Measure Analyze Tools & Methodology Better Faster Financials UCL LCL Avg
Results Driven IPO Diagram Six Sigma Better Material Type Amount of A Temperature Design Type SOPs Cell Layout Design Piece Flow Manpower Setup SOPs Maintenance SOPs Cell Cleanliness Supplier Lean S Yield Cost Space Process Product Time Process Setup Lead Capacity Delay Labor y Travel (Material) CODN (Finance) Team Dynamics Turnover Rate Communication Inventory In-Process Storage Throughput
Lean , pioneered by Toyota, focuses on the efficient operation of the entire value chain.
Focus areas :
Remove non-value added steps to:
Reduce cycle time
Align production with demand.
Improve process safety and efficiency.
Six Sigma , developed by Motorola, made famous by GE, it can be defined as a:
Measure of process capability
Set of tools
Vision for quality
Lean Sigma is a combination of two powerful and proven process improvement methods Lean and Six Sigma, that builds on existing organization capability in quality, statistics, and project execution. What is Lean and Six Sigma?
Lean Sigma: A Set of Tools Map the process to determine where defects are being created RISK PRIORITY NUMBER (RPN) = SEVERITY X 0CCURRENCEX ESCAPED DETECTION 5 4 3 2 1 Severe High Moderate Minor Negligible Occurrence Very High High Moderate Low Very Low (OCC) Severity (SEV) Escaped Very High High Moderate Low Very Low Detection (DET) Category Score Document failure modes for products and processes to identify defects' root cause ˆ s = ¯ s + A 2 A + B 2 B + AB 2 A • B Run 2 3 1 - - + 2 - + - 3 + - - 4 + + + A B AB y 1 y y . . . s 1 - - + 2 - + - 3 + - - 4 + + + ˆ y = y + A 2 A + B 2 B + AB 2 A • B Designed experiments to make process robust to variation Use control charts to understand & identify common & special causes Item Operator 1 Operator 3 Test 1 Test 2 Test 1 Operator 2 Test 1 Test 2 Test 2 1 2 3 4 5 6 7 8 9 10 Glass Inspection Test Measurement System Analysis Verify assessment/ measurement systems
Cycle Time Reduction Variance Reduction JIT Quick Changeovers Single Piece Flow Mapping Logical Physical Time 5Ss Visual Controls IPO CE CNX FMEA MSA Testing Correlations Hypothesis DOE Lean Six Sigma
Combining Lean and Six Sigma Maximizes the Potential Benefits Six Sigma – Improve Quality Lean – Remove Steps Drive Improvement
+4 +5 +6 +1 +2 +3 -2 -1 -4 -3 -6 -5 0 WASTE Determined by the customer Lower Specification Limit Upper Specification Limit Determined by the customer 3 Process
3 Process Centered
We make more than
customer needs because
some of what we make
Process is WIDER than
Sigma Capability The number of Sigmas between the center of a process and the nearest specification limit 3 Process has 66,807 dpm vs 3.4 from a 6 process +4 +5 +6 +1 +2 +3 -2 -1 -4 -3 -6 -5 0 6 Process
6 Process Centered
We make as much as
the customer needs
and have very little
Process FITS within
The First Step is Process Knowledge Return on Investment The 1 st Step is Process Knowledge Process Improvement Long Term Success
80 Percent of the Gain with 20 Percent of the Complexity
Most of the improvement is possible with the basic quality and statistical tools.
Tool Complexity Improvement 80% 20%
Sustained Improvements without Capital Dollars
Process improvements from Lean Sigma Projects are sustained.
Typically, results are audited at 4 and 12 months after implementing changes.
Discover the Relationship between the Inputs and Outputs
Identify the Root Causes of the Problems
Identify and Test the Proposed Solutions
Document Results and Return on Investment
Take Actions to Hold the Gains
Celebrate and Communicate
Mary Ann “Sally” Ulman teaches and consults on the subject of applications of statistical methods. She is an experienced facilitator in the areas of team building, problem solving, metric development, and implementation of process improvement strategies. Ms. Ulman left Chevron, USA after sixteen years where she worked as a Quality Facilitator, Corrosion Engineer, and Industrial Water Treatment Technologist throughout Central California and Sumatra, Indonesia. She has taught and consulted for Chevron, Caltex Pacific Indonesia, GlaxoWellcome in Pakistan, GlaxoSmithKline in Bangkok, Kuala Lumpur, London, Jakarta and India, Texaco, Baker Petrolite, Aera Energy, National Association of Corrosion Engineers, Farwest Corrosion, Mazda USA, Teac America, American Business Communications, California Training Cooperative, Auto Meter, PLCs Plus, United Way Agencies and various public seminars. Her extensive consulting background involves industrial and service applications of DOE, SPC, LeanSigma, reliability, management and team building techniques. She received her B.A. in Physical Education from California State University, Northridge. She attained Six Sigma Black Belt certification from University of Texas and Master Black Belt certification from Air Academy Associates. In addition she also holds a California Junior College Teaching Credential, Corrosion Technologist and Coating Inspection Certification from the National Association of Corrosion Engineers. She is now President of Variance Reduction International Inc. and works as an instructor and consultant for Air Academy Associates and is the Six Sigma instructor at San Diego State University. Variance Reduction International, Inc. President, Sally Ulman