Process Improvement Methodologies References (sources of graphics): (1)Fiore, Clifford, Accelerated Product Development: Combining Lean and Six Sigma for Peak Performance, Productivity Press, NY, NY, (2)Hamilton, Bruce, “Toast Kaizen, An Introduction to Continuous Improvement & Lean Principles,” Greater Boston Manufacturing Partnership, University of Massachusetts, Boston, MA, 2005 (DVD). (3)Insights On Implementation-Improved Flow: Collected Practices and Cases, Ralph Bernstein, Editor, Productivity Press, (4)Jacobs, Robert F. and Chase, Richard B., Operations and Supply Management: The Core, 2 nd Edition, McGraw-Hill/Irwin, NY, NY, (5)Nahmias, Steven, Production & Operations Analysis, 5 th Edition, McGraw-Hill/Irwin, NY, NY, (6)Nave, Dave, “How to Compare Six Sigma, Lean, and the Theory of Constraints,” Quality Progress, March 2002, pgs 73 – 78.

Comparison of Three Commonly Adopted Improvement Methodologies See reference, How To Compare Six Sigma, Lean and the Theory of Constraints See reference, How To Compare Six Sigma, Lean and the Theory of ConstraintsHow To Compare Six Sigma, Lean and the Theory of ConstraintsHow To Compare Six Sigma, Lean and the Theory of Constraints Comparing the main points of the three improvement methodologies: Six Sigma, Lean Thinking, and Theory of Constraints Comparing the main points of the three improvement methodologies: Six Sigma, Lean Thinking, and Theory of Constraints Comparing the main points of the three improvement methodologies: Six Sigma, Lean Thinking, and Theory of Constraints Comparing the main points of the three improvement methodologies: Six Sigma, Lean Thinking, and Theory of Constraints

Six Sigma Approach Define, measure, analyze, improve, control (DMAIC) cycle Define, measure, analyze, improve, control (DMAIC) cycle

Six Sigma Tools Tools common to other quality programs are used in Six Sigma Tools common to other quality programs are used in Six Sigma Tools common to other quality programs are used in Six Sigma Tools common to other quality programs are used in Six Sigma Failure mode and effects analysis (FMEA) Failure mode and effects analysis (FMEA) –Structured approach to identify, estimate, prioritize, and evaluate risk of possible failure at each stage of a process –Risk priority number (RPN) is calculated and is based on Extent of damage resulting from failure (severity) Extent of damage resulting from failure (severity) Probability failure takes place (occurrence) Probability failure takes place (occurrence) Probability of detecting the failure (detection) Probability of detecting the failure (detection) –High RPN items are designated for improvement first –Example Example Design of experiments (DOE) Design of experiments (DOE) –Statistical approach used for determining the cause-and-effect relationship between process variables and an output variable –Approach allows for experimentation with many variables simultaneously

Six Sigma Quality To achieve a Six Sigma quality (according to the assumptions used by Motorola and GE) a process must produce no more than 3.4 defects per million opportunities To achieve a Six Sigma quality (according to the assumptions used by Motorola and GE) a process must produce no more than 3.4 defects per million opportunities Assuming a process follows a normal distribution and given design limits of ± 6 σ there would be 2 defective parts per billion ( fraction defective) Assuming a process follows a normal distribution and given design limits of ± 6 σ there would be 2 defective parts per billion ( fraction defective) Motorola’s and GE’s value of 3.4 defects per million is due to the fact that a shift of 1.5 σ in the process mean is assumed Motorola’s and GE’s value of 3.4 defects per million is due to the fact that a shift of 1.5 σ in the process mean is assumed An example process An example process –spec = ± 0.005, μ = 1.250, σ = 0.002, UCL & LCL = 3 σ (μ and σ estimated from sample parameters) –Six Sigma process: μ = in, σ = in (0.005 in/6) –Six Sigma process with a 1.5 σ shift to the mean: μ = in, σ = in

Process Capability Index Process capability index (C pk ) Process capability index (C pk ) For (Motorola’s and GE’s) Six Sigma process For (Motorola’s and GE’s) Six Sigma process

Example Problem

Lean Case Study Quality Parts Company Quality Parts Company Quality Parts Company Quality Parts Company