Six Sigma and Beyond Statistical Process Control, Volume IV

In this volume of the Six Sigma and Beyond series, quality engineering expert D.H. Stamatis focuses on how Statistical Process Control (SPC) relates to Six Sigma. He emphasizes the "why we do" and "how to do" SPC in many different environments. The book provides readers with an overview of SPC in easy-to-follow, easy-to-understand terms. The author reviews and explains traditional SPC tools and how they relate to Six Sigma and goes on to cover the use of advanced techniques. In addition, he addresses issues that concern service SPC and short run processes, explores the issue of capability for both the short run and the long run, and discusses topics in measurement.

Introduction What is statistical process control (SPC)?The need for improvementOverviewHow to effectively direct the SPC effort?What is ideal process control?How to pull it offProblem solving techniquesOverviewTeam conceptTools and techniques Problem solving difficultiesSelected bibliographySummarizing dadaOverviewSummarizing dataGraphical presentationSelected bibliographyDescriptive statisticsOverviewMeasures of central tendenciesMeasures of dispersionNormal distributionOverviewCharacteristics of the normal distributionStandardized values(Z)Underlying distribution analysisMethods of testing for underlying distributionsProcess variation and control chartsOverviewCommon variationSpecial variationProcess control and process capabilityParts of control chartControl chart goalsThe relationship of variation to mean to normal distribution and to control chartReferencesSelected bibliographyPreparing for control chartsOverviewThe data orientationSampling considerationThe frequency of the sampleControl charts - preliminary issuesOverview of control chart developmentControl chart formReferencesSelected bibliographyVariable ChartsOverviewXbar and R chartX and MR chartXbar and s chartControl chart with slopping center lineCuSum chartReferencesSelected bibliographyAttribute chartsOverviewp chartnp chartc chartu chartThe weighted number of defects (D) chartReferencesSelected bibliographyOther chartsOverviewMedian chartStandardized charts for attribute dataDifference control chartThe lot plot methodModified control chartsTool wear and trend analysisControl charts based on weighted averageMiscellaneous control chartsMethods for controlling several related quality characteristicsStatistical alternatives to control chartsEvolutionary operationReferencesControl chart signalsOverviewCommon variationSpecial variationOut of control pointsThe runs testControl charts and hypothesis testingOther out of control indicationsStatistical analysis of control conditionsStatistical analysis of runsStatistical analysis of trendsReferencesSelected bibliographyCapabilityOverviewCapability analysisProcess and machine capabilitySteps for studying process capabilityInterpreting capability resultsCapability indicesMotorola's 6 sigmaComments on traditional and 6 sigma capabilityReferencesSelected bibliographyShort run SPCOverviewDefinition of short runCoded dataTarget valuesSampling considerationsShort run variable chartsShort Run Attribute control chartsInterpretation of short run chartsRecalculating targets, not control limitsRecalculating target valuesMeasuring capability ReferencesSelected bibliographyDistribution shape and stabilityOverviewCapability analysis and non normal distributionTrending processes and control chartsTrending processes and capabilitySelected bibliographyMeasurement system analysisOverviewMeasurement error vocabulary and conceptsBasic measurement error analysis (MEA)Control charts measurement stabilityMeasurement error analysis and advanced statistical methodsLoad the computer softwareReferencesSelected bibliography Machine acceptanceOverviewPhase I: Preliminary investigating machine warm-up and supplier's previous studiesPhase I examplePhase II: Preliminary study investigating process stability and capability descriptionPhase II examplePhase III: Recommended yes/no acceptance. A study predicting long term capabilityPhase IIII exampleFinal stepUsing the computer. A full description of how to use MINITAB and SPC with machine acceptance type dataTypical Phase II computer sessionSelected bibliographySPC for non manufacturingOverviewCriteria for successReaction versus PlanningImplementation strategyToolsProcess improvementReferencesSelected bibliographyAppendix A: General StatisticsHow do you compute averageControl limits for Xbar and RchartsControl limits for p chartsCommon SPC formulaeFormulae for calculating control chart limitsCapability Control chart construction guide - variable dataControl chart construction guide - attribute dataTesting for normality and exponentialityAppendix B: Production Part Approval Process (PPAP)Appendix C: Deming's Management PrinciplesAppendix D. Quality needs and overall strategic planAppendix E. Statistical tablesAppendix F. FormsFlow process chartVariable control chart formAttribute control chart formControl chart - process log sheetData collection sheet for capability analysisCapability analysis sheetCapability analysis - normal distributionCapability analysis - skew distribution