1、Process Failure Mode and Effects Analysis(Process FMEA)SCOPE DEFINITION(Step 1)Company Name:Name of company responsible for PFMEASubject:Name of PFMEA projectSystem/sub-system/component/part:Name of system elementPlant Location:Geographical locationPFMEA Start Date:Date PFMEA project startedPFMEA ID
2、 Number:Determined by the companyCustomer Name:Name of customer(s)or product family PFMEA Revision Date:Date of most recent changeProcess Responsibility:Name of PFMEA ownerModel Year/Platform:Customer application or company model/styleCross-Functional Team:Team Roster neededConfidentiality Level:Bus
3、iness Use,Confidential,Propriotary,etc.STRUCTURE ANALYSIS(Step 2)FUNCTION ANALYSIS(Step 3)FAILURE ANALYSIS(Step 4)RISK ANALYSIS(Step 6)OPTIMIZATION(Step 6)RemarksCONTINUOUSIMPROVEMENT1.Process ItemSystem,Subsystem,PartElement or Name of Process2.Process StepStation No.and Name of FocusElement3.Proce
4、ss Work Element Man,Machine,Material(Indirect),Milieu(Environment),etc.1.Function of the Process Item In-plant,Ship to plant,ProcessItem,Vehicle End user,whenknown 2.Function of the Process Stepand Product Characteristic(Quantitative value is optional)3.Function of the Process WorkElement and Proces
5、sCharacteristic1.Failure Effects(FE)In-plant,ship to plant,processitem,vehicle end user,whenknowOriginal Severity(S)of FE2.Failure Mode(FM)of theProcess Element3.Failure Cause(FC)of the WorkElementCurrent PreventionControl(PC)of FCOccurrence(O)of FCCurrent DectectionControls(DC)of FC orFMDetection(D
6、)of FC/FMAction Priority(AP)Special Product CharFilter Code(optional)Prevention ActionDetection ActionResponsiblePersonTargetCompletionDate(TCD)Status:Open,Completed,DiscardedAction Takenwith Pointerto EvidenceCompletionDateSeverity(S)Occurrence(O)Detection(D)Action Priority(AP)History/ChangeAuthori
7、zation(AsApplicable)The name of the process beinganalyzed e.g.electrical motorassembly line which is the endresult of all successfullycompleted process stepsmay also be a non-directmanufacturing process e.g.shippingThe operation or station to beanalyzed that produces theProcess Item e.g.OP30 Sintere
8、dbearing Press-in processUse the 4Ms to identity types ofvariation that have an influenceon the operation or station beinganalyzed4M Types:Man,Machine,Material(indirect),Milieu(Environment)List a single M for each line.Types may vary by companyA description of what theProcess Item is expected toachi
9、eve broken down intoseveral categoriesSome categories maybeunknown and listed as NotApplicable(NA)These expectations can bereferred to when completingFailure Effects(FE)These expected results mayapply for the entire Process Iteme.g.electrical motor assemblylineIn-plant：Avoid rework andscrapShip to p
10、lant Installation ofwindow lifter electrical motor tovehicle doorProcess Item.：Shaft installedinto pole house assemblyVehicle.：Window raises andlowersA description of what theoperation or station mustachieve e.g.Axial positionsintered bearing in pole housingThis is the positive ProductCharacteristic
11、 and must bedetectable in the productThe Failure Mode or FailureModes will be the negative ornegatives of the positive ProductCharacteristic.The Product Characteristic canbe written stating the entirepositive Product Characteristic,eg within gap tolerance,or usingseparate lines,considering overand u
12、nder tolerance,e g,notgreater then max tolerance,notless than min tolerance.It mayalso consider magnitude of outto tolerance if it effects theFailure Effects e.g.gap notgreater then max tolerance by03mm or gap not greater thenmax tolerance-More than 3 mmA positive description of how thework is compl
13、eted including thepositive process characteristicrelated to each 4MThe negative of these positiveswill be used for the FailureCause column The more detailused here will produce moreFailure Cause i.e.each line is aunique positive producing aunique negative,i.e.a FailureCauseInstead of“Get correct sin
14、teredbearing from part rack and placeinto fixture”Use“Get correctsintered bearing”and“Fullyplace bearing into fixture”Thisidentifies of two separate FailureCauses,i.e.“wrong part picked”“Bearing not fully set into fixture”The more detail used,the moreCauses can be captured in thedocumented for risk
15、analysis.Other possible positive processcharacteristic-“Pick part frompart rack without scratching thetop surface”,“Place part intofixture without using too muchforce”.Apply torque to bolt untilgreen light appears.Applytorque to bolt until green lightappears but not beyond.“Pickcorrect lubrication”.
16、“Applycorrect volume of lubrication”New Product Characteristicand Failure Modes-Whileconsidering“Function of theProcess Work Element andProcess Characteristic”new“Product Characteristics”.“Failure Causes”and“FailureModes”maybe generated,i.e.listing.“Pick part from part rackwithout scratching the top
17、surface”,may generate a newFailure Cause.“Scratched topsurface while picking part fromrack”and a new“ProductCharacteristics”,“Top surfacescratch free”and new FailureMode“Top surface scratched”How the Vehicle,System orSubsystem could fail to performthe Function described at theNext Higher levelWhen c
18、onsidering Effects,consider items listed in“Functionof the Process Item”and theFailure Mode”end how they canEffect the 3 areas beingconsidered(In-Plant,Ship toplant.Process Item,Vehicle EndUser)Include potential effects to thevehicle(End User)level endregulations.as applicableIt is recommended to li
19、st theSeverity Rank next to each ofthe 3 areas being consideredand use the highest Rank for theSeverity Rank.One area,suchas End User.may not alwayshave the highest Severity Rank110Failure mode must be detectablein the product(defect)The Failure Mode will be thenegative or negatives of thepositive P
20、roduct Characteristic.Considering each side of thespecification of ProductCharacteristic if specification ofProduct Characteristic has arange,list Failure Mode for eachside of the specification,i.e.,“Torque Bolt to spec”,the FailureModes will be“Torque loss thenspec”,“Torque more than spec”Each may
21、have a differentSeverity Rank.Considering magnitude of out ofspecification If the magnitude ofout of specification can affect theSeverity Rank.It should helisted,i.e.,“No stamping cracks”,the Failure Modes could becrack 0-10 mm long”,SeverityRank 4.“Crack greater than 10mm but less than 20 mm long”.
22、Severity Rank 7.“Crack 20 mmor greater”Severity Rank 10.Each will have its ownOccurrence Ranks.Controls,etc.When using a spreadsheet toperform the Failure Analysis it isrecommended to begin withFailure Modes then identifyFailure Effects and Causes.The Failure Cause is thenegative of the positive lis
23、ted in“Function of the Process WorkElement and ProcessCharacteristic”Cause must be detectable in theprocess(error)and lead to theFailure ModeNew Failure Causes-Whileconsidering“Failure Causes”,new Function of the ProcessWork Element and ProcessCharacteristic”,“ProductCharacteristic and maybegenerate
24、d,i.e.listing.“Scratchedtop surface while picking partfrom rack”can generate“Pickpart from part rack withoutscratching the top surface”,maygenerate and a new“ProductCharacteristics”,“Top surfacescratch tree”and a new FailureMode“Top surface scratched”Failure Analysis can begin withthe FM.FF or FC as
25、 long asthere is an accurate FailureChainInitial State-Pastcontrols proven and/orcontrols committed to110Initial State-Pastcontrols proven and/orcontrols committed to110H,M,L,NALLAdditional Actionsneeded to reduceOccurrenceAdditional Actionsneeded to improveDetectionName,nottitle ordepartmentmm yy o
26、r ddmm yyOptional:Decisionpending,Implementation pendingDescription ofaction takenanddocumentnumber,report nameand date,etc.mm yy or ddmm yy110 110 110 H,M,L,NAFor PFMEAteam useExamples:A design change:DCN0983885A managementreview:MR07-NOV-2017A customerreview:CR02-FEB-2018Electrical MotorOP 30 Sint
27、ered bearing pressOperatorProcess Item:Convert electricalenergy into mechanical energy(acc.control signal)In Plant:Assembly ofcomponents within cycle time,without scrap or reworkShip to Plant:Assembly of motorto vehicle door without linestoppage,sort or containmentEnd User Window raises andlowersPre
28、ss in sintered bearing toachieve axial position in polehousing to max gap per printOperator takes clean sinteredbearing from chute and push itonto the press-in shaft until theupper stopProcess Item:Loss ofmechanical energy because oftoo much friction betweenbearing and shaft,inner diameterof the bea
29、ring deformed becauseoff too much seating stressIn Plant:NoneShip to Plant NoneEnd User:Window raises andlowers with difficulty8Axial position of sintered bearingis not reached,gap too smallOperator inserts a sinteredbearing which was dropped tothe ground floor before(contaminated with dirt)No Preve
30、ntion control10Lot release Protectobjective(effectiveity100%)Visual Gaugeinspection of axial gapof bearing to polehousing eat by operator(check the checker:N/A)Dectection indicator:OK/NOK(RED/GREENarea)and operatorseparate the NOK part2HCCThe definition of awork instruction anda work instruction for
31、falling componentsand contents of theregularTraining curricularthe operator andfinishing staffJohn Doe(ProductionEngineer)DD.MM.YYYYIn-progress832LElectrical MotorOP 30 Sintered bearing pressMachine(press machine)Process Item:Convert electricalenergy into mechanical energy(acc.control signal)In Plan
32、t:Assembly ofcomponents within cycle time,without scrap or reworkShip to Plant:Assembly of motorto vehicle door without linestoppage,sort or containmentEnd User Window raises andlowersPress in sintered bearing toachieve axial position in polehousing to max gap per printMachine has to press in thesin
33、tered bearing into the polehousing seat until the definedaxial positionProcess Item:Loss ofmechanical energy because oftoo much friction betweenbearing and shaft,inner diameterof the bearing deformed becauseoff too much seating stressIn Plant:NoneShip to Plant NoneEnd User:Window raises andlowers with difficulty8Axial position of sintered bearingis not reached,gap too smallMachine stops before rea
