Lean Manufacturing/Operations7 Quality ToolsCG. RobinsonPsychologySystem ThinkingTheory of KnowledgeCHANGEData CollectionRun ChartsHistogramsControl ChartsCause & EffectParetoScatter DiagramsRadar / Glyph ChartsVariationUnderstanding VariationDisplay & UnderstandInvestigate Sources Lean Manufacturing/OperationsCG. RobinsonRecap Previous lecture1. Data collection2. Run Charts 3. Histograms4. Control Chartsspecial cause variationcommon cause variationCp & Cpk5. TamperingLean Manufacturing/OperationsMeasuresControl or Process Behaviour ChartsCG. RobinsonDateTotal DeliveriesSuMTWThFSSuMTWThFSSuM10/110/210/310/410/510/610/710/810/910/1010/1110/1210/1310/1410/15 10/16319305284252301526499290319258276309462508327274TWTh10/1710/18 10/19384145343972574938414137577543441020304050607080903411433158113042018321Number Late XrMean x 46.9UCL x 76.69LCL x 17.11spreadLean Manufacturing/OperationsMeasuresProcess CapabilityThe voice of the processA process must be stable before it is considered capableA process capability index is a technique for summarising the capability and location of a process that is in statistical controlNever compute a process capability index for a process that is not in statistical controlUse graphs like control charts and histograms to support any statistical indices reportedCG. RobinsonLean Manufacturing/OperationsMeasuresProcess CapabilityFurther DataCG. RobinsonThe tolerance of late deliveries the business can stand is between 44 and 64. (the specification)So the upper spec limit is 64 and the lower spec limit is 44Lean Manufacturing/OperationsMeasuresProcess Capability=ENGINEERING SPECIFICATIONUSLLSLET=R_=1.128STANDARD DEVIATION DATA3Sd6Sd.SdSdSd3Sd6Sdxx36=CAPABILITY INDECES (Cp)6SdETCp.PROCESS APABILITY INDEX (Cpk)=.X_-USLDA3SdCpk upper=-.X_LSLDB3SdCpk lowerCpk WARNING, ONLY CONTINUE IF PROCESS IS STABLE AND PREDICTABLE CG. RobinsonLean Manufacturing/OperationsMeasuresProcess Capability=ENGINEERING SPECIFICATIONUSLLSLET=R_=1.128STANDARD DEVIATION DATA3Sd6Sd.SdSdSd3Sd6Sdxx36=CAPABILITY INDECES (Cp)6SdETCp.PROCESS CAPABILITY INDEX (Cpk)=.X_-USLDA3SdCpk upper=-.X_LSLDB3SdCpk lowerCpk WARNING, ONLY CONTINUE IF PROCESS IS STABLE AND PREDICTABLE 11.2644420206446.917.146.9442.9.098Quote the lower value of the twoCG. Robinson-9.929.759.4.33659.49.9.575.09769.929.729.7Lean Manufacturing/OperationsMeasuresControl or Process Behaviour ChartsCpwidth of the processwidth of engineering toleranceCG. RobinsonShort Run SPC Using Deviation From AimIn short run SPC, were making a few parts of different sizes, so we cant really use the actual measurements. Instead of evaluating the variation of each measurement, we use the variation of parts from a target value. So, if the first group of parts has a target value of 74mm, we measure each part and determine the variation from the target. If the next group of parts has a target value of 60mm, we measure those and determine their variation. Ideally, the variation from the target value will remain stable even though the parts vary in size. Lean Manufacturing/OperationsControl or Process Behaviour ChartsBar LengthMTWThF10/210/310/410/510/6-.10-.2-.1+.500.20.40.60,8DateSizer.1.2.1.6- 0.2- 0.4- 0.6- 0,8Part A 2,60 +/- .08Deviation2,52,62,42,53,1MTWThF10/210/310/410/510/6-.3-.2-.2-.3+.100.20.40.60,8r,10,1,4- 0.2- 0.4- 0.6- 0,8MTWThF10/210/310/410/510/61,51,91,31,31,700.20.40.60,8r,4,2,6,4- 0.2- 0.4- 0.6- 0,8Part B 3,40 +/- .08Part C 1,50 +/- .083.13,23,23.13.5+,4-,2-,2+,20Lean Manufacturing/OperationsControl or Process Behaviour ChartsShort Run SPC Using Deviation From AimPart A = 2,60 +/- .08Bar LengthPart B = 3,40 +/- .08Part C = 1,50 +/- .08MTWThF10/210/310/410/510/600.20.40.60,8DateSizer- 0.2- 0.4- 0.6- 0,8Deviation-.10-.2-.1+.506162,52,62,42,53,1PartAAAAA-.3-.2-.2-.3+.122023.13,23,23.13.51,51,91,31,31,73601+,4-,2-,2+,2041BCBCBCBCBCLean Manufacturing/OperationsControl or Process Behaviour ChartsShort Run SPC Using Deviation From AimLean Manufacturing/OperationsMeasuresControl or Process Behaviour ChartsCG. RobinsonLean Manufacturing/OperationsMeasuresControl or Process Behaviour ChartsCG. RobinsonVideo “A Japanese Control Chart”Which control chartUse X-MR chartIs it Variables Data?Sub Group Size = 1?Use XR chartCan the data being collected be larger than the subgroup?Equal sized subgroups?Equal sized subgroups?Use c-chart or u-chartUse u-chartUse np-chart or p-chartUse p-chartNo (attributes data)yesyesyesyesyesnonononoLean Manufacturing/OperationsCG. RobinsonLean Manufacturing/OperationsControl or Process Behaviour ChartsCG. RobinsonTypes & where to use themLean Manufacturing/OperationsMeasuresControl or Process Behaviour ChartsCG. RobinsonLean Manufacturing/OperationsMeasuresControl or Process Behaviour ChartsCG. Robinson“The Deming management Method, Mary Walton, Pages 105 to 107 & 111 to 116 isbn 1-85252-141-4“A Study of the Toyota Production System, Shingeo Shingo, Pages 16 to 17, isbn 0-915299-17-8“The Lean Toolbox, John Bicheno, Pages 174 to 175, Short Run SPC,