失效模式及其影响分析讲座(英文版).ppt

FAILUREMODEandEFFECTSANALYSIS失效模式及其影响分析,PhilipsCFTAsiaPacificInnovation,SxOxD,RPN125,SODDescriptionAction?1011Failureunlikelytoreachuser1101FrequentMinor,detectablefailure1110Minordefectreachesuserinfrequently10101Seriousandfrequentfailure11010Frequentminordefectreachesuser10110Seriousdefectreachesuser101010INTROUBLE!,Step5-EstablishActionsandResponsibilities,1.Whathastobeimproved:-changeofdesign-lifetest-contactwithsupplier-controlpointbuildin,inproductionprocessetc.2.Whoisresponsible3.Whenisitfinished,RPNacceptable?,Correctiveactions,DO,NewRPN1,Acceptable?,End,Yes,No,No,Yes,RPNacceptable?,Correctiveactions,DO,NewRPNn,Acceptable?,End,Yes,No,No,Yes,ChoiceofCorrectiveActions,UnlikelytobeeffectivePreferredchoices*Increaseinspection*Poka-yoke(fool-proofing)*Additionaltest*Processchange*Additionalcheck*designchange*Re-trainoperators*Automation*Re-writeSOP*Computerisation*Robotics,CorrectiveActionPreferenceHierarchy,TheintentofanyrecommendedcorrectiveactionistoimprovetheRPNratingbyreducingSeverity,Occurrence,Detectionorall3together.Emphasisshouldbeonprevention,i.e.reducingOccurrence.Shouldpreventionbeimpossible,thefollowingHierarchyofpreferenceshouldbeused:1.Prevention,orpotentialcauseelimination2.Detection,asearlyintheproductlifecycleaspossible:bestatthedesignstagenextbestpriortomassproductionthenpriortoshipmentand,aslastresortinthefield,priortocatastrophicfailure3.Impactreduction,i.e.reduceSeverityGenerally,toreduceanyofthethreerating-O,D,S-processand/ordesignchanges/modificationarerequired,FMEA,isisnot*structured*ashow-piece*systematic*anumbergame*rigorous*aguessinggame*comprehensive*adocumentationexercise*scientific*aself-consolationexercise*adiscipline.*preventive.*customer-focused.*ateameffort.*across-functionalexercise.*alivingdocument.*acontinuousprocess*aone-offexercise,RealLifeFMEAExercise,3PRODUCTD-FMEA,ProcessFMEAvsProductD-FMEA,*P-FMEAdoesnotrelyonproductdesignchangestoovercomeprocessweaknesses,butitdoestakeintoconsiderationaproductsdesigncharacteristics*D-FMEAdoesnotrelyonprocesscontrolstoovercomedesignweaknesses,butitdoestakethetechnical/physicallimitationsofthemanufacturingprocess(i.e.theprocesscapability)intoconsideration.,Processstep,Purpose,Piece-partorsub-assy,Function,ProcessFMEA,ProductFMEA,ProcessFMEAvsProductD-FMEA,*Hencecausessuchas“operatornotinsertingresistorproperly”noisy;jerky;cannotwhatthecustomerwouldobserverunathighspeedand/orexperienceNexthigherleveleffectseffectsontheengineover-heated;vibrationLocaleffectseffectsonthevalveitselfdeterioration,MATERIAL,USE,DESIGN,COMPONENT,SPECIFICATION,ENVIRONMENT,PRODUCT,ProductCause-EffectInvestigation,ProductFunctions,ProductFunctions,ProductFunctions,Severity(D-FMEA),RatingDegreeEffects1Minor*noperceptibleeffectonproductperformance*userwillprobablynotnoticethefailure3low*customernoticesslightdeteriorationinperformance*causesslightcustomerannoyance5Moderate*causessomecustomerdissatisfaction*customernoticesreducedproductperformance*gradualperformancedeterioration7High*highdegreeofcustomerdissatisfaction*lossofsub-systemfunction,eg.enginefail10Veryhigh*safety-related*non-compliancewithgovernmentregulations,Occurrence(D-FMEA),RatingDescriptionProbabilityoffailureDesignlifefailurerate1RemoteFailureunlikely1ppm3LowRelativelylowfailurerate200ppm1000ppm5ModerateOccasionalfailures2500ppm1in80(1.25%)7HighRepeatedfailures1in40(2.5%01in20(5.0%)10VeryhighFailurealmostinevitable1in8(12.5%)1in2(50.0%),Detection,ApproachDescriptionApplicationTime-tableHowearlyinproductlifecycleD-FMEAfromdesignstarttoFieldfailure?Fixed-gateWhatstheprobabilityofdetectionD-FMEAatanypoint(gate)inthecycle?,Detection(D-FMEA),Time-tableapproachRatingProbabilityofdetection1WillbedetectedpriortoProductionRelease3VerylikelytobedetectedpriortoFinalRelease4DetectableafterreleasebutbeforeMassProduction5DetectablepriortoShipment7Willbedetectedbeforeoccurrenceinthefield10Undetectableuntilfailureoccursinthefield,Detection(D-FMEA),FixedGateapproachRatingProbabilityofdetection1Willbedetectedindesignevaluations3Highchanceofdetectionindesignevaluations5Moderatechanceofdetectionindesignevaluations7Lowchanceofdetectionduringdesignevaluations10Undetectableuntilfailureoccursinthefield,4ORGANIZATIONALASPECTSOFFMEA,OrganisationalAspectsofFMEA,GeneralPointsParticipantsPreparationsReporting,FMEAisateameffortcoveringallrelevantdisciplinesFMEAsessionsshouldnotlastlongerthanhalfadayTheproductFMEAshouldbefocusedon:-reliability(normalfunctioning)-producibilityTheprocessFMEAshouldbefocusedon:-processflow-manipulationsofoperator-deviationsinmaterial-transport-storage,GeneralPoints,FMEA:CriticalSuccessFactors,*Behonest*Bepositive*Bethorough*Attentiontodetails*Followthrough*Involvetherightpeople*“Ratherbesafethansorry”*Managementbyfact-Minimiseguess-workandgut-feel-Maximiseuseofdataandquantitativemethods,Participants,ParticipantsshouldbedirectlyinvolvedNumberofparticipantsshouldbelimitedParticipantsfromrelevantdepartments:-Development-Engineering-Production-Process-Quality-Specialist(ifnecessary)-Service,PreparationsforD-FMEA,Preparationsshouldbedonebythedesigner,incloseco-operationwiththechairmanofthemeetingDrawingsandsufficientmodelsshouldbeavailableOnemodelshouldhavebeenincirculationTolerancecalculationsandcontourmapsshouldbeavailableSpecialpreparationsforaD-FMEA:-thedesignshouldbebreakdownintoelements-prioritysettingsoftheseelements-fromexistingproductsthefollowingdatashouldbeavailable:.Presaledata.Servicecallratefigures.Fallofffigures,Reporting,ResultofFMEAreportedonstandardformsActionlistshouldbesetupfromthesessionandshouldbe:-presentedonthemilestonemeetings-knownandtrackedwithintheprojectteam-discussedateveryprojectteammeeting,5MATURITYGRID,UseoftheMaturityGrid,Objective:Totrackmaturityindesignofproduct&processTofacilitateMilestonedecisionsTovisualisestatus:alsoproblemstobesolvedinthenextphasesInputsforMaturityGrid:OutstandingDesignIssues(TechSpec,CustomerRequirements)ProblemsfoundinDesignEvaluation/ProcessTrailsProblemsfoundinReliabilitytestsPotentialproblemsidentifiedinFMEAsessions,FMEAprovidesinputtothematuritygrid,butisnottheonlyone!,MaturityGridforProducts&Processes,GravityFactor:S-nonconformitywithsafetystandard/otherrequirementA-productnotproducibleorsaleableB-notacceptedbycriticalcustomerorproductionwithbigproblemsC-canbesoldorproducedwithminordifficultiesD-problemaccepted(noactions)EvolutionFactor:4-causenotknown3-solutionnotknown2-evaluationnotyetpositive1-solutionnotyetintroduced0-solutionsintroduced,Product/Processmaturitygrid,GravityFactor,EvolutionFactor,S,A,