【正文】 176。 Note: Time is a Factor Only if Temperature Changes Significantly Step 9.....Establish Tolerances on “Vital Few” (Xs) How do we Ensure Oven Temperature is Controlled? ? Data Suggests 350 ( 5 ) is best Temperature to Reduce Taste Variation ? Brand A Flour to be Used Except in Case of Emergency ? “BETTER BREAD” to Search for Better Alternative Supplier of Flour Just in Case 176。 176。 Z T Target 0 A 3? Process The Definitions of Yield Final Test Process (Process 4) Pass Process 3 Process 1 Process 2 100 (Units Tested) 65 70 82 91 Yield 1 Yield 2 Yield 3 Loss 1 Loss 3 Rejects Loss 2 9 9 12 5 ? First Time Yield (Yft) = Units Passed Units Tested = 65 70 = ? Rolled Thruput Yield (Yrt) = (Yield 1) (Yield 2) (Yield 3) . . . . = 91 82 65 70 ( ( ( ( ) ) ) ) = 100 91 70 82 ? Normalized Yield (Ynm) = = 1/n (Yrt) () 1/4 = ( n: Total Number of Processes ) 6? Overview Yield Exclusive of Rework Probability of Zero Defects Average Yield of All Processes 6? Overview The Impact of Complexity Rolled Yield Number of Operations .4 .1 1 10 100 1,000 10,000 1,000,000 Process Mean Centered on Each Operation 1 10 100 1,000 10,000 1,000,000 Rolled Yield Number of Operations .5 As the Number of Operations Increases, a High Rolled Yield Requires a High ??for Each Operation 5?? 4?? 3?? 6?? 6?? 5?? 4?? 3??Process Mean Shifted ??at Each Operation 6? Overview Baselining Benchmarking an Existing Process p (x) Defects Benchmark Baseline Entitlement ? Benchmark.....A WorldClass Performance ? Entitlement.....Achievable Performance Given the Investments Already Made ? Baseline.....The Current Level of Performance Baselining = Current Process / Benchmarking = Ultimate Goal Some Basic 6?Related Tools 6? Overview Scatter Diagram Over Slept Car Would Not Start Weather Family Problems Other Pareto Diagram Frequency of Occurence Reasons for Being Late for Work Arrival Time at Work Time Alarm Went Off Materials People The Histogram Control Charts 6? Overview Some Basic 6?Related Tools The Fishbone Diagram Measurements Methods Technology Statement Cause Effect Being Late for Work Plot of Daily Arrival Time 9:15 7:00 7:15 7:30 7:45 8:00 8:15 8:30 8:45 9:00 Average Value Number of People Arriving at CRD Time 6? Overview LCL UCL Range Chart R Out of Control Condition LCL X UCL X Bar Chart Some Basic 6?Related Tools LCL = Lower Control Limit UCL = Upper Control Limit X = Mean R = Average Range Monitors Changes in Average or Variation Over Time Design of Experiments 6? Overview SCREENING OPTIMIZATION CHARACTERIZATION ? For Experiments Involving a Large Number of Factors ? Useful in Isolating the “Vital Few “ from the “Trivial Many” ? For Experiments Involving a Relatively Small Number of Factors ? Useful When Studying Relatively Unplicated Effects Interactions ? For Experiments Involving Only 2 or 3 Factors ? Useful When Studying Highly Complicated Effects Relationships DOE is More Effective Than Testing One Factor at a Time 6? Overview Using the “One Factor at a Time” Approach Reduce Commute to Work to 15 Minutes (without working an abnormal work schedule) The Goal The Variables Time of Departure from Home Route Taken to Work The Approach Try 3 Potential Routes at Current Departure Time (7:45), Select the Best Vary the Departure Time ?til we get to 15 Minutes Time of Departure 3 2 1 7:15 7:30 7:45 8:00 8:15 Route Combination Selected The Result Use Route 2 and Leave at 7:15 to Reach Goal 6? Overview Using “Design of Experiments” (DOE) Time of Departure DOE (i) Better Accounts for Interactive Variables Missed by “One Factor at a Time”, and (ii) Efficiently Searches for “Sweet Spot” in Parameter Space The Variables Time of Departure from Home Route Taken to Work The Approach Vary time of Departure and Route Simultaneously, in a Systematic Fashion The Result A Better Combination Allowing 15 More Minutes of Sleep!!! Actual Commuting Time Averages (minutes) 3 2 1 7:15 7:30 7:45 8:00 8:15 Route 17 20 23 21 19 15 18 20 19 16 12 15 21 20 18 Original Conclusion Best Combination “Sweet Spot” Reduce Commute to Work to 15 Minutes (without working an abnormal work schedule) The Goal A Practical Example (The “Cookbook”) 6? Overview 6?.....and Baking Bread YEAST FLOUR Using a 12 Step Process 6? Overview The “BETTER BREAD” Company Step 1.....Selecti