10 Steps to Conduct a PFMEAWord格式.docx
- 文档编号:17036622
- 上传时间:2022-11-28
- 格式:DOCX
- 页数:14
- 大小:125.72KB
10 Steps to Conduct a PFMEAWord格式.docx
《10 Steps to Conduct a PFMEAWord格式.docx》由会员分享,可在线阅读,更多相关《10 Steps to Conduct a PFMEAWord格式.docx(14页珍藏版)》请在冰豆网上搜索。
∙AssignOccurrencerankings—Basedonhowfrequentlythecauseofthefailureislikelytooccur.
Step6
∙AssignDetectionrankings—Basedonthechancesthefailurewillbedetectedpriortothecustomerfindingit.
Step7
∙CalculatetheRPN—SeverityXOccurrenceXDetection.
Step8
∙Developtheactionplan—Definewhowilldowhatbywhen.
Step9
∙Takeaction—ImplementtheimprovementsidentifiedbyyourPFMEAteam.
Step10
∙CalculatetheresultingRPN—Re-evaluateeachofthepotentialfailuresonceimprovementshavebeenmadeanddeterminetheimpactoftheimprovements.
Step1:
ReviewtheProcess
Reviewtheprocesscomponentsandtheintendedfunctionorfunctionsofthosecomponents.
∙Useofadetailedflowchartoftheprocessoratraveler(orrouter)isagoodstartingpointforreviewingtheprocess.
Thereareseveralreasonsforreviewingtheprocess
∙First,thereviewhelpsassurethatallteammembersarefamiliarwiththeprocess.Thisisespeciallyimportantifyouhaveteammemberswhodonotworkontheprocessonadailybasis.
∙Thesecondreasonforreviewingtheprocessistoidentifyeachofthemaincomponentsoftheprocessanddeterminethefunctionorfunctionsofeachofthosecomponents.
∙Finally,thisreviewstepwillhelpassurethatyouarestudyingallcomponentsoftheprocesswiththePFMEA.
Usingtheprocessflowchart,labeleachcomponentwithasequentialreferencenumber.
∙ThesereferencenumberswillbeusedthroughouttheFMEAprocess.
∙Themarked-upflowchartwillgiveyouapowerfulvisualtorefertothroughoutthePFMEA.
Withtheprocessflowchartinhand,thePFMEAteammembersshouldfamiliarizethemselveswiththeprocessbyphysicallywalkingthroughtheprocess.Thisisthetimetoassureeveryoneontheteamunderstandsthebasicprocessflowandtheworkingsoftheprocesscomponents.
Foreachcomponent,listitsintendedfunctionorfunctions.
∙Thefunctionofthecomponentisthevalue-addingrolethatcomponentperformsorprovides.
∙Manycomponentshavemorethanonefunction.
Step2:
BrainstormPotentialFailureModes
InStep2,considerthepotentialfailuremodesforeachcomponentanditscorrespondingfunction.
∙Apotentialfailuremoderepresentsanymannerinwhichthecomponentorprocessstepcouldfailtoperformitsintendedfunctionorfunctions.
UsingthelistofcomponentsandrelatedfunctionsgeneratedinStep1,asateam,brainstormthepotentialfailuremodesforeachfunction.
∙Don’ttakeshortcutshere;
thisisthetimetobethorough.
Prepareforthebrainstormingsession.
∙Beforeyoubeginthebrainstormingsession,reviewdocumentationforcluesaboutpotentialfailuremodes.
Step3:
ListPotentialEffectsofFailure
Determinetheeffectsassociatedwitheachfailuremode.Theeffectisrelateddirectlytotheabilityofthatspecificcomponenttoperformitsintendedfunction.
∙Aneffectistheimpactafailurecouldmakeifitoccurred.
∙Somefailureswillhaveaneffectonthecustomersandothersontheenvironment,thefacility,andeventheprocessitself.
Aswithfailuremodes,usedescriptiveanddetailedtermstodefineeffects.
∙Theeffectshouldbestatedintermsmeaningfultoproductorsystemperformance.
∙Iftheeffectsaredefinedingeneralterms,itwillbedifficulttoidentify(andreduce)truepotentialrisks.
Step4:
AssignSeverityRankings
Assignaseverityrankingtoeacheffectthathasbeenidentified.
∙Theseverityrankingisanestimateofhowseriousaneffectwouldbeshoulditoccur.
∙Todeterminetheseverity,considertheimpacttheeffectwouldhaveonthecustomer,ondownstreamoperations,orontheemployeesoperatingtheprocess.
Theseverityrankingisbasedonarelativescalerangingfrom1to10.
∙A“10”meanstheeffecthasadangerouslyhighseverityleadingtoahazardwithoutwarning.
∙Conversely,aseverityrankingof“1”meanstheseverityisextremelylow.
Therankingscales(forseverity,occurrence,anddetection)aremissioncriticalforthesuccessofaPFMEAbecausetheyestablishthebasisfordeterminingriskofonefailuremodeandeffectrelativetoanother.
∙ThesamerankingscalesforPFMEAsshouldbeusedconsistentlythroughoutyourorganization.ThiswillmakeitpossibletocomparetheRPNsfromdifferentFMEAstooneanother.
∙See
FMEAChecklistsandForms
foranexamplePFMEASeverityRankingScale.
Thebestwaytocustomizearankingscaleistostartwithastandard,genericscaleandthenmodifyittobemoremeaningfultoyourorganization.
∙Asyouaddexamplesspecifictoyourorganization,consideraddingseveralcolumnswitheachcolumnfocusedonatopic.
∙Onetopiccouldprovidedescriptionsofseveritylevelsforoperationalfailures,anothercolumnforcustomersatisfactionfailures,andathirdforenvironmental,health,andsafetyissues.
foranexamplesofCustomPFMEARankingScales.(Examplesofcustomscalesforseverity,occurrence,anddetectionrankingsareincludedinthisAppendix.)
Step5:
AssignOccurrenceRankings
Next,considerthepotentialcauseorfailuremechanismforeachfailuremode;
thenassignanoccurrencerankingtoeachofthosecausesorfailuremechanisms.
Weneedtoknowthepotentialcausetodeterminetheoccurrencerankingbecause,justliketheseverityrankingisdrivenbytheeffect,theoccurrencerankingisafunctionofthecause.Theoccurrencerankingisbasedonthelikelihood,orfrequency,thatthecause(ormechanismoffailure)willoccur.
Ifweknowthecause,wecanbetteridentifyhowfrequentlyaspecificmodeoffailurewilloccur.Howdoyoufindtherootcause?
∙Therearemanyproblem-findingandproblem-solvingmethodologies.
∙Oneoftheeasiesttouseisthe5-Whystechnique.
∙Oncethecauseisknown,capturedataonthefrequencyofcauses.Sourcesofdatamaybescrapandreworkreports,customercomplaints,andequipmentmaintenancerecords.
Theoccurrencerankingscale,liketheseverityranking,isonarelativescalefrom1to10.
∙Anoccurrencerankingof“10”meansthefailuremodeoccurrenceisveryhigh,andhappensallofthetime.Conversely,a“1”meanstheprobabilityofoccurrenceisremote.
foranexamplePFMEAOccurrenceRankingScale.
Yourorganizationmayneedanoccurrencerankingscalecustomizedforalow-volume,complexassemblyprocessoramixtureofhigh-volume,simpleprocessesandlow-volume,complexprocesses.
∙Considercustomizedoccurrencerankingscalesbasedontime-based,event-based,orpiece-basedfrequencies.
forexamplesofCustomPFMEARankingScales.(Examplesofcustomscalesforseverity,occurrence,anddetectionrankingsareincludedinthisAppendix.)
Step6:
AssignDetectionRankings
Toassigndetectionrankings,identifytheprocessorproductrelatedcontrolsinplaceforeachfailuremodeandthenassignadetectionrankingtoeachcontrol.Detectionrankingsevaluatethecurrentprocesscontrolsinplace.
∙Acontrolcanrelatetothefailuremodeitself,thecause(ormechanism)offailure,ortheeffectsofafailuremode.
∙Tomakeevaluatingcontrolsevenmorecomplex,controlscaneitherpreventafailuremodeorcausefromoccurringordetectafailuremode,causeoffailure,oreffectoffailureafterithasoccurred.
∙Notethatpreventioncontrolscannotrelatetoaneffect.Iffailuresareprevented,aneffect(offailure)cannotexist!
TheDetectionrankingscale,liketheSeverityandOccurrencescales,isonarelativescalefrom1to10.
∙ADetectionrankingof“1”meansthechanceofdetectingafailureiscertain.
∙Conversely,a“10”meansthereisabsolutecertaintyofnon-detection.Thisbasicallymeansthattherearenocontrolsinplacetopreventordetect.
foranexamplePFMEADetectionRankingScale.
TakingaleadfromAIAG,considerthreedifferentformsofCustomDetectionRankingoptions.CustomexamplesforMistake-Proofing,Gauging,andManualInspectioncontrolscanbehelpfultoPFMEAteams.
∙(Examplesofcustomscalesforseverity,occurrence,anddetectionrankingsareincludedinthisAppendix.)
Step7:
CalculatetheRPN
TheRPNistheRiskPriorityNumber.TheRPNgivesusarelativeriskranking.ThehighertheRPN,thehigherthepotentialrisk.
TheRPNiscalculatedbymultiplyingthethreerankingstogether.MultiplytheSeverityrankingtimestheOccurrencerankingtimestheDetectionranking.CalculatetheRPNforeachfailuremodeandeffect.
∙EditorialNote:
ThecurrentFMEAManualfromAIAGsuggestsonlycalculatingtheRPNforthehighesteffectrankingforeachfailuremode.Wedonotagreewiththissuggestion;
webelievethatifthissuggestionisfollowed,itwillbetooeasytomisstheneedforfurtherimprovementonaspecificfailuremode.
Sinceeachofthethreerelativerankingscalesrangesfrom1to10,theRPNwillalwaysbebetween1and1000.ThehighertheRPN,thehighertherelativerisk.TheRPNgivesusanexcellenttooltoprioritizefocusedimprovementefforts.
Step8:
DeveloptheActionPlan
TakingactionmeansreducingtheRPN.TheRPNcanbereducedbyloweringanyofthethreerankings(severity,occurrence,ordetection)individuallyorincombinationwithoneanother.
AreductionintheSeverityranking
- 配套讲稿:
如PPT文件的首页显示word图标,表示该PPT已包含配套word讲稿。双击word图标可打开word文档。
- 特殊限制:
部分文档作品中含有的国旗、国徽等图片,仅作为作品整体效果示例展示,禁止商用。设计者仅对作品中独创性部分享有著作权。
- 关 键 词:
- 10 Steps to Conduct PFMEA