WCM精华之QC-Workshop

1QCWorkshopDr.H.YamashinaProfessorEmeritus,KyotoUniversityFellowofRCA(TheU.K.)MemberofRoyalSwedishAcademyofEngineeringSciences19thJuly,20072Contents1.Japan’sQCHistory2.WhatIstheQCProblemSolvingApproach?3.TheQCViewpoint–VitalforQC-TypeProblemSolving4.QualitySpecificationandProcessCapability5.HowtoImproveProcessCapability6.QualityAssuranceofEveryQualityItem7.TheQCSevenStepFormula–SolvingProblemstheQCWay8.TheFourMajorFactors–InfluencingProcessCapability9.ProcessingPointAnalysis10.DiagnosticTabletoCheckQualityControlKeyQuestions3CHAPTER1Japan’sQCHistory4TheDevelopmentofJapan’sQualityControl:aLongJourneyVision,strategySatisfactionsofstakeholdersManagementR&DMarketingProductplanningDesignProductionpreparationBusinessManufacturingtechniquesPurchasingManufacturingQualitycontrolInspectioncontrolInspectionQCProcessQCTotalQualityControlTQM5Majorconceptaboutqualityassurance(ingeneral)1Inspection-orientedqualityassuranceThefirststageofqualityassurance,whichfocusesmainlyoninspectionoffinalproducts,involvesonlytheinspectiondepartmentandthequalitydepartment.Theirmainfunctionsaretopreventdefectiveproductsfrombeingreleasedfromthecompany.Limitations(a)Inspectorsdonotbuildinquality.Theyareextrapeople,whichreduceslaborproductivity.(b)Theresponsibilityofqualityassurancedoesnotbelongtotheinspectiondivision,buttothedesignandproductiondivisions.6(c)Itisliabletotaketoomuchtimetofeedbackinformationfromtheinspectiondivisiontotheproductiondivision.(d)Astheproductionspeedisincreased,itbecomesimpossibletomakeinspectionbyhumanbeingproperly.(e)Inordertocarryoutqualitycontrolintermsofppm,thestatisticalsamplingmethodforAQLdoesnotwork.(f)Therearealotofitemswhichcannotbeguaranteedbyinspection.(g)Ifdefectivesareproducedoneafteranotheratprocesses,itisnousecarryingoutstrictinspection.72Process-orientedqualityassuranceThesecondstageofqualityassurance,whichfocusesonprocesscontrol,involvestheworkshops,subcontractors,thepurchasingdepartment,theproductionengineeringdepartmentandeventhebusinessdepartment.“100%goodqualityispursuedbyinvestigatingprocesscapabilitycarefullyandcontrollingtheproductionprocessproperly.”“Build-inqualityattheprocess.”We(Toyota)arenotinterestedinbuyingproductsfromthecompanieswhichsellgoodproducts,butinterestedinbuyingproductsfromthecompanieswhichhavegoodproductionprocesses.8Thebasicprincipleofqualityassurance:Buildinqualityattheprocess.Theinvestigationanddeterminationofinspectionmethods,measuringequipment,orinspectionfacilitiesatprocessesbecomemajorissues.1.Fromthestageofdesigning,qualityproblemsmustbeinvestigated.2.Throughtrials,hiddenproblemsmustbediscovered.3.Theknowledgeaboutqualityandmaintenanceproblemsatexistingprocessesmustbeusedwhenestablishingnewproductionlines.94.100%assuranceoftheprocesscapabilityforqualitymustbemade.5.Themethodofinspectingtheinitialproduct(try-out)anditsfeedbacktoimprovetheprocessesmustbeclarified.6.Developmentofinspectionequipmentattheprocessisvital.7.Introductionoffoolproofdevicestopreventhumanmistakesmustbemade.Limitation(a)Theproblemswhichcamefrombaddevelopmentanddesigncannotbesolvedbytheproductionandinspectiondivisions.(b)Themis-selectionofmaterialcannotbesolvedbyprocesscontrol.103QualityassuranceinnewproductintroductionThethirdstageofqualityassurance,whichstartsfromdevelopinganewproduct,requirescompany-wideactivitiesfromplanningofthenewproducttoreleasingtheproducttocustomers.Qualityguaranteeatthisstageofdevelopingthenewproducteventuallymeansthatqualitycontrolmustbedonewiththeparticipationofallthedivisionsandalltheemployeesincludingsubcontractors.“Build-inqualityatthedesignandtheprocess.”11Reasons(a)IfQCisnotpursuedproperlyinnewproductintroduction,satisfactoryqualityguaranteecannotbemade.(b)Ifthecompanymakesafailureinnewproductintroduction,itbecomesamatterofsurvivalordeathforthecompany.(c)Qualityassuranceinnewproductintroductioninvolvesresearch,planning,designing,trialproduction,purchasing,productiontechnology,production,inspection,businessafterservicedepartments.12procurement10050ThedeterminationcurveoftheproductioncostThegenerationcurveoftheproductioncost0DevelopmentDesignPrototypeMaterialsManufacturingDeliveryCostweightTheDeterminationCurveandtheGenerationCurveoftheProductionCostFig.1.2:13IdealTimeforModificationsIdealtimeformodificationsWorsttimeformodificationsPossibilityofqualityandproductivityimprovementCostofmodificationsConceptDevelopmentValidationProductionFig.1.314PhenomenaSpecsProcessCausesProcessmajoreffectsmediumeffectsminoreffectsDefectmode(custo-mer)DefectiveproductsectionQualitycharacteristicsDefectivemodePrcoesssequenceProcessname123ProcessQAmatrixArticlenameArticlenumberPersonHeadManagerInchargeTable1.1QAMatrix15Table1.2QAMatrixA:effectbigB:effectmediumNameofproduct:ABCNameofprocessQAmatrix(Productdevelopmentmanagement)Itemsofproductguaranteeandthedegreeofinfluence(Productdevelopmentmanagement)QualityguaranteeitemsateachprocessGuaranteecharac-teristicsDefectmodeEstimatedcauseThedegreeofinfluenceThedegreeofoccurrenceThedegreeofdetectionChemicalcharac-teristicsElectriccharac-ter