ProcessFailureModeand

EffectsAnalysis

過程失效模式及后果分析(PFMEA)

PFMEA

PFMEA陶國第一頁，共六十二頁。ProprietaryInformation

專有信息YourFMEA(ControlPlan,ProcessCapability,etc.)maybeconsideredproprietaryandshouldnotbesharedwithanyoneoutsidethedivisionwithoutfirstconsultingyourmanagement.FMEA(控制計劃、過程能力等)可視為專有信息，在未事先征得管理部門同意之前，不得向部門以外的任何人透露。thisincludesthesharingofinformationwithyourcustomer 也不得向顧客透露有關信息。第二頁，共六十二頁。FormsandFormats

形式和格式Yourcustomermighthaveaspecificformatorformthattheyrequire.Ifso,youwillneedtogettheirwrittenapprovaltouseanalternateformat.顧客可能要求特定的格式或表單。如果是這樣，你只有征得他們的書面同意，才能采用其它格式。第三頁，共六十二頁。ProcessFMEA

過程FMEA何謂PFMEA何時作PFMEA何人作PFMEA如何作PFMEA16步工作步驟第四頁，共六十二頁。ProcessFMEA

過程FMEA何謂PFMEA何時作PFMEA何人作PFMEA如何作PFMEA16步工作步驟第五頁，共六十二頁。ProcessFMEA

過程FMEAananalyticaltoolusedbyaprocessdesignteamtoidentifypotentialproductfailurescausedbyfailureofthemanufacturingandassemblyprocesstomeetrequirements,andidentifycorrectiveactionstobetaken是過程設計小組采用的一種分析方法，用于識別由于制造或裝配過程的失效而導致的潛在產品失效模式，并確定所應采取的糾正措施。第六頁，共六十二頁。formalprocess 正式程序customerfocused 著眼于顧客usesengineeringjudgment,andharddatawhereitisavailable 利用工程經驗判斷和可靠的數據ProcessFMEA

過程FMEA第七頁，共六十二頁。PFMEAisfocussedontheProductPFMEA關注對產品的影響ProcessFMEA

過程FMEA第八頁，共六十二頁。ProcessFMEA

過程FMEA何謂PFMEA何時作PFMEA何人作PFMEA如何作PFMEA16步工作步驟第九頁，共六十二頁。WhendowedoaPFMEA?

何時進行PFMEA？Whilethereisstilltimetobringaboutchangesintheprocessandintheproduct! 當還有時間修改產品及工藝設計時！APFMEAdonesolelytofilloutaformandmeet“requirements”isjustanexercise 為了滿足QS9000要求而填寫PFMEA表格，僅是練習而已第十頁，共六十二頁。PFMEAisanoutputofthe"ProcessDesignandDevelopment"phaseofAPQP

PFMEA是APQP中“過程設計和開發”階段的產物WhendowedoaPFMEA?

何時進行PFMEA？第十一頁，共六十二頁。ItisderivedfromaDFMEA

在DFMEA之后進行AnyDFMEAformsandsupportingdocumentsshoudbebroughttothePFMEAmeetings DFMEA表單和所有相關文件都應帶入PFMEAItshouldbeanaturalpartofconceptdevelopment應成為過程設計的一個必要組成部分PFMEAisnever“finished”.itisalivingdocument是動態文件WhendowedoaPFMEA?

何時進行PFMEA？第十二頁，共六十二頁。DoaPFMEA(oratleastreviewtheoldone)if:以下情況需進行PFMEA(或至少評審過去的PFMEA)：theprocessisnew是新的過程theproductisnew,orhasneverbeenmadewiththisprocess 新產品，或從未用本過程加工的產品anexistingprocesschanges 原有的過程發生變化customerrequirementsordesireschange 顧客要求或希望發生變化WhendowedoaPFMEA?

何時進行PFMEA？第十三頁，共六十二頁。DoaPFMEA(oratleastreviewtheoldone)if:以下情況需進行PFMEA(或至少評審過去的PFMEA)：thecompetitive,business,orlegalenvironmentchanges 競爭環境、業務環境或法律環境發生變化PPAPconditionsapply 需提交PPAPactualfailuresoccur 發生實際失效WhendowedoaPFMEA?

何時進行PFMFA？第十四頁，共六十二頁。ProcessFMEA

過程FMEA何謂PFMEA何時作PFMEA何人作PFMEA如何作PFMEA16步工作步驟第十五頁，共六十二頁。WhoperformsaPFMEA?

由誰進行PFMEA？Across-functionalteamshouldbeused 由跨部門小組進行Theleadershouldbetheprocess-responsibleengineer 小組組長應是過程設計責任工程師第十六頁，共六十二頁。Cross-FunctionalTeam

跨部門小組5-9peoplefrom，5-9人，由從事如下工作的人員組成

Design，設計Assembly，裝配manufacturing(operators,supervisors)，制造(操作工，班組長)Industrial,mfg.Andtoolengineering，工業工程，工藝及工裝設計quality，質量管理materialsengineering，材料工程Servicepersonnel，機修Supplierofproductandmachinery，零件和設備供應商Representativesfromthenextprocess,后續工序代表第十七頁，共六十二頁。ProcessFMEA

過程FMEA何謂PFMEA何時作PFMEA何人作PFMEA如何作PFMEA16步工作步驟第十八頁，共六十二頁。HowdowedoaPFMEA?

ASummary

怎樣進行PFMEA？提要Assemblethecross-functionalPFMEAteam 組建跨部門PFMEA小組Listthefailuremodes,theireffects,andtheircauses 列出失效模式，后果以及原因第十九頁，共六十二頁。Assess， 評估 theseverityoftheeffect(S) 后果的嚴重程度thelikelihoodofthecauses(O) 原因出現的可能性 andtheabilityofprocesscontrolstodetectfailuremodesand/ortheircauses(D) 過程控制探測失效模式和/或原因的能力HowdowedoaPFMEA?

ASummary

怎樣進行PFMEA？提要第二十頁，共六十二頁。Calculatetheriskprioritynumber(RPN)toprioritizecorrectiveactions計算風險順序數(RPN)以確定應優先采取的糾正措施Plancorrectiveactionsandassignowner 制訂糾正措施并落實責任人Performcorrectiveactionstoimprovetheproductorprocess,采取糾正措施以提高產品和過程質量RecalculateRPN 重新估算RPNHowdowedoaPFMEA?

ASummary

怎樣進行PFMEA？提要第二十一頁，共六十二頁。HowdowedoaPFMEA?

ASuggestion

怎樣進行PFMEA？建議Doyourworkonscratchpaperfirst;astheteamreachesconsensus,recordtheinformationontheFMEAform 先在一張草稿紙上進行分析；當小組達成一致意見后，再將有關信息填在FMEA表上usefishboneandtreediagramsliberally充分利用魚刺圖和樹形圖tryingtousetheFMEAformasaworksheetleadstoconfusionandmessed-upFMEAs

若將FMEA表當做工作單使用，就會造成混亂，使FMEA一塌糊涂第二十二頁，共六十二頁。ProcessFMEA

過程FMEA何謂PFMEA何時作PFMEA何人作PFMEA如何作PFMEA16步工作步驟第二十三頁，共六十二頁。1.Assembleateamand

planyouractivities

成立小組并制訂計劃PFMEAmustneverbedonebyanindividual,because 絕不能由個人單獨進行PFMEA，因為：individualeffortsproducebiasedresults, 由個人進行會使結果出現偏差anyactionswillrequirebuy-infromvariousgroups 進行任何活動，都需要從不同的組織取得信息第二十四頁，共六十二頁。Oneperson(e.g.theleader)shouldbeassignedtomaintainingtheFMEAform 應指定一個人(如組長)保管FMEA表格BesuretowritethenamesandfunctionsoftheteammembersontheFMEAform 應將小組成員的姓名和職責填入FMEA表格1.Assembleateamand

planyouractivities

成立小組并制訂計劃第二十五頁，共六十二頁。2.Developaprocessflowdiagram

繪制過程流程圖UsetheProcessFlowDiagramformat 運用正規的過程流程圖identifiesfabricate,move,storeandinspectoperations辨別四種作業類型identifiesKeyCharacteristics 辨別關鍵特性第二十六頁，共六十二頁。

Supplier________________ Date_______________PartNumber_____________ RevisionLevel______PartDescription__________ Preparedby_________pressuremoldpartfabmovestoreinspstepoper.descr.item#KPCitem#KCCinspectpartforflashstorepartincontainercarrypartstoassyarea1noflash112342.Developaprocessflowdiagram

繪制過程流程圖第二十七頁，共六十二頁。過程流程圖moldpart注塑零部件fab加工move搬運store存放insp檢驗step步驟oper.descr.作業說明item#編號KPCitem#編號KCCinspectpartforflash檢驗零件有無飛邊storepartincontainer將零部件放入周轉箱內carrypartstoassyarea將零部件送往裝配區1noflash無飛邊pressure壓力11234第二十八頁，共六十二頁。第二十九頁，共六十二頁。3.Listthefunction(s)of

eachoperation

列出每個操作的功能Afunctioniswhattheoperationdoes 功能系指該操作所起的作用Statethefunctionas，說明功能為：Verb+Object+Qualifier動詞+賓語+修飾詞

moldpart，零件成型 crimpterminalontocable 在線端壓接端子 formbendinpart,零件彎曲成型examples例如第三十頁，共六十二頁。Don'tforgetauxiliaryfunctionsaswellaprimaryfunctions 基本功能和輔助功能都要考慮3.Listthefunction(s)of

eachoperation

列出每個操作的功能第三十一頁，共六十二頁。4.Listthequality

requirements

列出質量要求acustomerwantordesire 顧客的希望或要求couldseriouslyaffectcustomerperception 有可能嚴重影響顧客的看法couldleadtoacustomercomplaint 有可能導致顧客投訴第三十二頁，共六十二頁。5.Listthepotentialprocessfailuremodes

列出可能的過程失效模式adefect,flaw,orotherunsatisfactoryconditionintheproductthatoccurswhentheprocessfailstomeettheprocessrequirements 由于過程未達到要求而導致的產品缺陷、瑕疵等不良狀態failuremodesshouldbewrittenintermsoftheconditionoftheproduct 失效模式體現在產品上第三十三頁，共六十二頁。TypicalFailureModes，幾種典型失效模式diameteroutofspec.，直徑超差missingseal，漏裝密封墊cutstrands，切破線皮misorientedpart，部件方向錯insufficientsolder，焊劑不足toomuchsolder，焊劑過量NFO，未充滿Flash，飛邊5.Listthepotentialprocessfailuremodes

列出可能的過程失效模式第三十四頁，共六十二頁。Note，注Assumethatincomingproductandmaterialsarecorrect 假設來料沒問題Assumethattheproductasdesignedwillmeetrequirements 假設產品設計能夠滿足客戶需求5.Listthepotentialprocessfailuremodes

列出可能的過程失效模式第三十五頁，共六十二頁。6.Derivethepotentialeffectsofeachfailure

列出每一失效模式的所有可能后果Theramificationsoffailure 后果是失效模式的衍生事件Theeffectcanbeon，可能影響theultimatecustomer，最終用戶orintermediatecustomer(OEM,etc.)，中間用戶agovernmentregulation，法規thenextprocessstep，下序第三十六頁，共六十二頁。Customercomplaintsareausefulsourceofinformation 顧客抱怨是非常有用的信息來源6.Derivethepotentialeffectsofeachfailure

列出每一失效模式的所有可能后果第三十七頁，共六十二頁。Aneffectcanbe，后果可能為completelossoffunction，功能完全喪失degradationofperformanceorquality，質量或性能降低damageofprocessequipment，設備受損injurytoanoperator，員工受傷shut-downofanassemblyline，停線6.Derivethepotentialeffectsofeachfailure

列出每一失效模式的所有可能后果第三十八頁，共六十二頁。Effectsoffailureoftenshowupasachainofevents,fromimmediateeffecttotheultimateeffectonthecustomer，失效的后果通常表現為從對顧客的直接影響到最終影響等一系列連鎖反應ItisrecommendedthatthesechainsbedevelopedforeachfailuremodeandrecordedontheFMEAform建議針對每一種失效模式找出這些連鎖反應，并記錄在FMEA表上useatreediagram 運用樹形圖6.Derivethepotentialeffectsofeachfailure

列出每一失效模式的所有可能后果第三十九頁，共六十二頁。Effectsontheprocess，對過程的影響:9-10 mayendangermachineoroperator， 可能導致設備或人員受損6-8 scrap，報廢4-5 sortandrework，檢驗、返工2-3 reworkon-line，線上返工1 noeffect，無影響consideralsotheeffectsonthecustomer還要考慮對顧客的影響7.Assesstheseverity

ofeacheffect

評估每種后果的嚴重度第四十頁，共六十二頁。Criteria:SeverityofEffect

Thisrankingresultswhenapotentialfailuremoderesultsinafinalcustomerand/oramanufacturing/assemblyplantdefect.Thefinalcustomershouldalwaysbeconsideredfirst.Ifbothoccur,usethehigherofthetwosev

Hazardous-withoutwarning10Veryhighseverityrankingwhenapotentialfailuremodeaffectssafevehicleoperationand/orinvolvesnoncompliancewithgovernmentregulationwithoutwarning.Ormayendangeroperator(machineorassembly)withoutwarning.

Hazardous-withwarning9Veryhighseverityrankingwhenapotentialfailuremodeaffectssafevehicleoperationand/orinvolvesnoncompliancewithgovernmentregulationwithwarning.Ormayendangeroperator(machineorassembly)withwarning.

VeryHigh8Vehicle/iteminoperable(lossofprimaryfunction).Or100%ofproductmayhavetobescrapped,orvehicle/itemrepairedinrepairdepartmentwitharepairtimegreaterthanonehour.

High7Vehicle/itemoperablebutatareducedlevelofperformance.Customerverydissatisfied.Orproductmayhavetobesortedandaportion(lessthan100%)scrapped,orvehicle/itemrepairedinrepairdepartmentwitharepairtimebetweenahalf-hourandanonehour.

Moderate6Vehicle/itemoperablebutComfort/Convenienceitem(s)inoperable.Customerdissatisfied.Oraportion(lessthan100%)oftheproductmayhavetobescrappedwithnosorting,orvehicle/itemrepairedinrepairdepartmentwitharepairtimelessthanahalf-hour.

Low5Vehicle/itemoperablebutComfort/Convenienceitem(s)operableatreducedlevelofperformance.Or100%ofproductmayhavetobereworked,orvehicle/itemrepairedoff-linebutdoesnotgotorepairdepartment.

VeryLow4Fit&Finish/Squeak&Rattleitemdoesnotconform.Defectnoticedbymostcustomers(greaterthan75%).Ortheproductmayhavetobesorted,withnoscrap,andaportion(lessthan100%)reworked.

Minor3Fit&Finish/Squeak&Rattleitemdoesnotconform.Defectnoticedby50%ofcustomers.Oraportion(lessthan100%)oftheproductmayhavetobereworked,withnoscrap,on-linebutout-of-station.

VeryMinor2Fit&Finish/Squeak&Rattleitemdoesnotconform.Defectnoticedbydiscriminatingcustomers(lessthan25%).Oraportion(lessthan100%)oftheproductmayhavetobereworked,withnoscrap,on-linebutin-station.

None1Nodiscernibleeffect.Orslightincoveniencetooperationoroperator,ornoeffect.第四十一頁，共六十二頁。8.Determinepotentialcause(s)ofeachfailuremode

確定每一失效模式的可能原因Acauseoffailureishowthefailurecanoccurintheprocess，失效原因：過程為何會失效Shouldbewrittenintermsofsomethingintheprocessthatcanbecorrectedandcontrolled，應表述為可糾正或可控制的因素Considerhumanerror,wear-outoftools,ambientconditions,andinteractionsoffactors，如人的過失，工裝磨損、環境條件以及因素間的相互作用第四十二頁，共六十二頁。Causesoffailureoftenshowupasachainofevents,fromimmediatecausetorootcause 失效通常是由一連串的原因造成的，從直接原因到根本原因ItisrecommendedthatthesechainsbedevelopedforeachfailuremodeandrecordedontheFMEAform 建議針對每一種失效模式，找出原因鏈，記入FMEA表useatreeorfishbonediagramtodevelop 可利用樹形圖或魚刺圖8.Cause(s)ofFailure

失效原因第四十三頁，共六十二頁。9.Assessthelikelihoodof

occurrenceofeachcause

評估每種失效原因產生的可能性Usehistoricaldata(asabaseline)，利用歷史資料Takeimprovementsintoaccount，并考慮所作的改進

Usestatisticalmodelsandcomparisonwithsimilarprocesses利用可靠性模型，與類似的過程進行比較第四十四頁，共六十二頁。9-10 Failurealmostinevitable，失效幾乎不可避免7-8 Similarprocessesthathaveoftenfailedin thepast，以前類似過程常常失效4-6 Similarprocessesthathaveoccasional failures，類似過程偶爾失效1-3 Similarprocessesthathaveexperienced isolatedfailures，類似過程僅有過個別失效9.Assessthelikelihoodof

occurrenceofeachcause

評估每種失效原因產生的可能性第四十五頁，共六十二頁。Occurence(O)ProbabilityLikelyFailureRates*VeryHigh:

PersistentFailures>=100per

thousandpiecesVeryHigh:

PersistentFailures50perthousandpiecesHigh:

FrequentFailures20perthousandpiecesHigh:

FrequentFailures10perthousandpiecesModerate:

OccasionalFailures5perthousandpiecesModerate:

OccasionalFailures2perthousandpiecesModerate:

OccasionalFailures1perthousandpiecesLow:Relatively

FewFailures0.5perthousandpiecesLow:Relatively

FewFailures0.1perthousandpiecesRemote:Failure

isUnlikely<=0.010perthousandpieces10987654321第四十六頁，共六十二頁。CausesandEffects

HarnessClampCause-and-effectchainradiusoutofspectoolisworntoolnotreplacedlackofmaintenanceprocedureclampcracksatbendbundlefallsoutrattlingnoiseCAUSEchainEFFECTchain第四十七頁，共六十二頁。CausesandEffects

WiringAssemblyEffectsTreeCrossedWireNofunctionFireinPlantOperatorInjuryDamagedEquip.Mustrepairvehicle第四十八頁，共六十二頁。CausesandEffects

WiringAssemblyCausesTreeCrossedWireBoardErrorOperatorErrorPoorInstruct.NottrainedOperistired第四十九頁，共六十二頁。10.ListtheCurrentProcessControls

列出現有過程控制Processcontrolscatchthedefectbeforetheproductreachesthecustomer，過程控制當在產品到達顧客前發現缺陷!TherearethreeTypesofprocesscontrols,過程控制有三種類型:(1)preventthecauseoffailure,orreducetherateofoccurrence，防止原因出現或降低其出現的可能性(2)detectthecause(s)offailureandleadtocorrectiveactions，查明失效的原因并找出糾正措施(3)detectthefailuremode(s)，檢測失效模式第五十頁，共六十二頁。Assigncurrentlyusedprocesscontrolstofailuremodesandcauses，針對失效模式或原因列出現行的過程控制手段Usedonsimilarprocessesinthepast，以前類似過程如何控制CanbeofanyType:1,2,or3,oranycombination，可以是1、2、3類或其組合Type1controlsaffectthelikelihoodofoccurrence,ifalreadypartofthedesign，若設計中已有體現，則第1類方法可降低原因出現的頻度Ifnone,write“None”，若沒有，則填“無”。10.ListtheCurrentProcessControls

列出現有過程控制第五十一頁，共六十二頁。Detectionisanassessmentoftheprobabilitythat，探測度為下列事件發生的概率atype2controlcandetectthecauseandleadtocorrectiveaction,第2類控制能夠發現原因并找到糾正措施 atype3controlcandetectafailure，第3類控制能夠在不良品到達顧客前發現缺陷 ...beforetheproductreachesthecustomer!detectioncanalsoassesshoweffectivelyatype1controlcanpreventfailure，第1類控制能夠預防失效的有效程度11.Detectingfailure

探測度第五十二頁，共六十二頁。11.Detectingfailure

探測度DetectionRating(D)，探測度評分(D) 9-10 veryremotechancethiscontrol willdetectthecauseorfailure 查明失效或其原因的可能性極小 7-8 remotechance，可能性很小 5-6 moderatetolowchance，可能性不大 2-4 moderatelytoveryhighchance，可能 性較大1 almostcertainly(ifthepartpasses thistest,it'sOKtoship) 幾乎都可以查到(如能通過這項檢測，則可放 心發貨)第五十三頁，共六十二頁。Detection(D)CriteriaInspection

TypesSuggestedRangeofDetectionMethods

ABC

AlmostImpossibleAbsolutecertaintyofnon-detection.

XCannotdetectorisnotchecked.VeryRemoteControlswillprobablynotdetect.

XControlisachievedwithindirectorrandomchecksonly.RemoteControlshavepoorchanceofdetection.

XControlisachievedwithvisualchecksonly.VeryLowControlshavepoorchanceofdetection.

XControlisachievedwithdoublevisualinspectiononly.LowControlsmaydetect.

X

XControlisachievedwithchartingmethods,suchasSPC{StatisticalProcessControl}.ModerateControlsmaydetect.

X

Controlisbasedonvariablegaugingafterpartshaveleftthestation,orGo/NoGogaugingperformedon100%ofthepartsafterpartshaveleftthestation.ModeratelyHigh

Errordetectionisinsubsequentoperations,ORgaugingperformedonsetupandfirst-piececheck(forset-upcausesonly).Controlshaveagoodchancetodetect.XX

High

Errordetectionin-station,orerrordetectioninsubsequentoperationsbymultiplelayersofacceptance:supply,select,install,verify.Cannotacceptdescrepantpart.Controlshaveagoodchancetodetect.XX

VeryHighControlsalmostcertaintodetect.

X

X

Errordetectionin-station(automaticgaugingwithautomaticstopfeature).Cannotpassdiscrepantpart.VeryHighControlscertaintodetect.

X

Discrepantpartscannotbemadebecauseitemhasbeenerror-proofedbyprocess/productdesign.InspectionTypes:A.Error-proofed,B.Gauging,C.ManualInspection第五十四頁，共六十二頁。12.CalculatetheRisk

PriorityNumber(RPN)

計算風險順序數(RPN)RPN = SxOxD = SeverityofEffect xOccurrenceRating xDetectionRating = 后果的嚴重度 x原因可能出現的頻度 x探測度FocusonhighRPNs 關注RPN較高的項目第五十五頁，共六十二頁。Rec