9 Process FMEA

1、Failure Mode and Effects AnalysisFMEA7/11/2022Failure Mode and Effects Analysis Learning ObjectivesAt the end of this section delegates will be able to:Understand the role of Failure Mode and Effects Analysis, FMEA within the DMAIC Improvement Process Conduct a Process FMEA on an existing, new or mo

2、dified transactional processUse the Process FMEA to prioritise areas for attentionUse the Process FMEA to support the generation of Control Plans2Failure Mode and Effects Analysis - AgendaIntroduction to Failure Mode and Effects AnalysisFMEA Within DMAICFMEA RoadmapFMEA Form and Control PlansImpleme

3、nting FMEASummary3“Classic FailuresCity trader buys 15,000,000 shares instead of 15,000Leap day shuts down bank cash machinesNASA probe lost due to Metric/Imperial units confusion Worldwide Perrier stocks withdrawn due to filter failurePilot shuts down wrong aircraft engineCompany emails confidentia

4、l account information to analysts and has to suspend trading4Introduction to FMEAFailure Mode and Effects Analysis, FMEA is:A systematic method of identifying and investigating potential design or process weaknesses.A means to evaluate and manage product risks.A means of evolving organizational know

5、ledge.Developed in the aerospace industry in the mid 1960s5FMEA PurposeRecognise and evaluate the potential failure modes and causes associated with the design and manufacture of a product or design and operation of any process.Identify actions which could eliminate or reduce the chance of the poten

6、tial failure occurring.Document the analysis and changes made.6Application of FMEA in Six SigmaIn Design for Six Sigma - (Design FMEA) :to identify potential failure modesto identify potential causes of failureto eliminate/minimise the potential failure modes within the Design processIn Transactiona

7、l/Operational Six Sigma (Process FMEA) :to analyse the existing processes (identify possible xs)to improve the process (elimination/reduction of failure modes)to select new process alternativesto develop control plans7Application of PFMEA in DMAICMeasure: Preliminary root cause analysisAnalyse:To an

8、alyse the existing processes and identify possible xs (causes of failure)Improve:To improve the process (elimination/reduction of failure modes)To select new process alternativesControl:To develop control plansIt is only necessary to conduct PFMEA on the modified/changed areas of the process8Links f

9、rom C&E MatrixKPOVsKPIVs9Process FMEA Roadmap1.Describe Process2.Define Functions3.Identify Potential Failure Modes4.Describe Effects of Failure5.Determine Causes6.Current Controls7.Calculate Risk8.Take Action9.Assess ResultsStep 1: Describe Process Process Flow Diagrams Error & Correction Data Inte

10、rnal Problem Data Customer FeedbackProcess Knowledge1.Describe Process11Suppliers:SalesStoresInputs:OrderProductPackaging Customers:SalesShippingEnd customerOutputs:Packaged ProductShipping requisitionOrder fulfilment noteStep 1: Describe Process- Order FulfilmentReceive orderCheck stockPull product

11、 and checkPackage productWeigh productCorrect weight?All available?Order stockNotify SalesTransfer to Goods OutYesYesNoNo1.Describe Process12ProcessFlowDiagramList of Functions(Purposes)Step 2: Define Function2.Define Functions13Action VerbNounGatherPublishApproveReleaseProjectReportCreditProductDat

12、aSalesTestPartCheckContactReceiveDeliverCalculateAddressCustomerStockOrderPriceAction VerbNounProcessInformationExamples of Functions2.Define Functions14Step 2: Define FunctionFunctions Receive order Check sufficient stock Notify sales Order stock Pull product Check product Etc.2.Define FunctionsRec

13、eive orderCheck stockPull product and checkAllavailable?Order stockNotify SalesYesNo15FunctionDoes Not Function?List of PotentialFailuresDoes not/CannotToo muchToo littleToo early Too lateDegradedIntermittentIncorrectUnwantedFunctionStep 3: Identify Potential Failure Modes3.Identify Potential Failur

14、e Modes16Process FunctionPotential Failure Modes Receive OrderDoes not receive orderReceives incorrect orderReceives too many orders Check sufficient stockDoes not check sufficient stockIncorrect check (wrong conclusion)Insufficient stock when sufficientSufficient stock when insufficientStep 3: Iden

15、tify Potential Failure Modes Notify SalesDoes not notify salesNotifies sales too lateNotifies sales with incorrect information17Assume the failure could occur - what would be the effect ?Consider :How it affects the process (processor):next operationsubsequent downstream operationsHow it affects the

16、 end user (customer).Immediate & delayed impact.Be realistic.Note: There may be several potential effects for each failure, but these are listed together as one overall effect.Step 4: Describe Effects of Failure4.Describe Effects of Failure18 Does not Receive Order Incorrect stock check (Concludes i

17、nsufficient when sufficient available)Step 4: Describe Effects of Failure4.Describe Effects of FailureAssume the failure could occur - what would be the effect?Potential Failure ModesPotential EffectsOrder not fulfilled, customer has to re-submit orderDelay in fulfilling order, excess stock, possibl

18、e loss of order Incorrect stock check (Concludes sufficient stock when insufficient available)Incomplete order, delay, customer dissatisfaction Notify Sales too lateCustomer not aware of delay, sales takes further orders 19What could cause the potential failure mode to occur ?Process / processor err

19、ors that could lead to the failureBe specific, “processor error or “equipment failure are too vagueConsider the working environment of the process, condition of equipment, IT systemsThere will typically be several causes for each failure modeIdentify root causes for severe failuresStep 5: Determine

20、Causes5.Determine Causes20Step 5: Determine CausesWhat could cause the potential failure mode to occur ?Potential CausesPotential Failure Modes Incorrectly addressed Delivered to wrong department Lost in post Does not receive order Incorrect stock check Error in inventory levels Entered wrong part c

21、ode Entered wrong quantity Multiple orders in process5.Determine Causes21For the given example, describe the process using a process flowchart. Describe each process step in terms of its function using a verb noun combination e.g. check stock, calculate profit , complete invoice, check form etc. (N.

22、B. depending on the detail of the flowchart there may be more than one function at each step).Working from the process flowchart, identify potential failure modes by adding the key words: does not/cannot/incorrect function, too much/too little function, too early/late function etc. Each function sho

23、uld have at least one failure mode.For each of the failure modes identify the potential effects of the failure on the process, processor and/or the customer. If there are several effects then group these together as the overall effect for the failure mode. Each failure mode should have one effect.Fo

24、r each failure mode, identify the possible causes of the failure. Be specific, “processor error is too vague. There will typically be more than one cause per failure mode. Prepare a short presentation on your teams findings.Workshop 1Time:Workshop 1:Identify Potential Failures Modes22Process FMEA Ro

25、admap1.Describe Process2.Define Functions3.Identify Potential Failure Modes4.Describe Effects of Failure5.Determine Causes6.Current Controls7.Calculate Risk8.Take Action9.Assess ResultsIn order of preference there are three types of current controls :Prevent the cause Detect the cause, leading to co

26、rrective actionDetect the failure (defect)These might include:Control ChartsCheck SheetsMistake ProofingTrainingInformation TechnologyIdentify the current controls to prevent / detect the failure before it reaches the customerStep 6: Current Controls6.Current Controls24Step 6: Current ControlsIncorr

27、ect stock checkError in inventory levelsEntered wrong part codeEntered wrong quantityMultiple orders in processStock take (annual), Stock control system Double entry requiredDouble entry requiredNo controlsPotential Failure Modes Identify the current controls to prevent / detect the failure before i

28、t reaches the customer6.Current ControlsPotential CausesCurrentControls25ProbabilityofOccurrenceDetection (Capability of Current Controls)RiskPriorityNumberXX=Step 7: Calculate Risk7.Calculate RiskSeverity ofthe Effect26Process FMEA Severity RatingHow serious is the effect ?Note : Many organisations

29、 choose to modify the descriptions to best describe their industry.SevEffectCustomer EffectProcessor Effect11HazardousSafety compromised or non-compliance with legal issueMay endanger processor or process equipment7HighLoss of serviceProcess stops, 100% transactions incorrect4ModerateVery dissatisfi

30、ed, service provided but much degradedSignificant process disruption, many transactions require correcting2LowInconvenient, service provided but not up to expectationsSome process disruption, some transactional reworking1Very minor / noneNot noticed by most customersMinor disruption to process or no

31、 effect27Process FMEA Occurrence RatingHow likely is the cause ?Note : Many organisations choose to modify the descriptions to best describe their industryOccProbabilityLikely failure rates11Very high, persistent failures1 in 10 transactions (opportunities)7High, frequent failures1 in 100 transactio

32、ns (opportunities) 4Moderate, occasional failures1 in 1,000 transactions (opportunities) 2Low, relatively few failures1 in 10,000 transactions (opportunities) 1Remote, failure is unlikely1 in 100,000 transactions (opportunities)28Process FMEA Detection RatingHow effective are the Current Controls?De

33、tCriteriaTypical Detection/Control MethodType11No ControlsCannot detect or is not checked?7Controls detect failureInspection, checking34Controls detect causeControl charts (focused on outputs)3/22Controls prevent failureControl charts (focused on inputs)2/11Controls prevent causeMistake Proofing, tr

34、aining129Effect Incomplete order, delay, customer dissatisfactionCause Multiple orders in processCurrent Controls No ControlsSeverity = 4 Occurrence = 4Detection = 11RPN = 4 x 4 x 11 = 176Step 7: Calculate RiskFailure ModeIncorrect Stock Check7.Calculate Risk30Corrective Action Effects On RPN Rating

35、Note : Do not modify RPN until corrective action is completed (Step 9)Step 8: Take Action8.Take Action31Effect Incomplete order, delay, customer dissatisfactionCause Multiple orders in processCurrent Controls No ControlsSeverity = 4 Occurrence = 4Detection = 11RPN = 4 x 4 x 11 = 176Step 8: Take Acti

36、onFailure ModeIncorrect Stock Check8.Take ActionStock Check is improved32Review corrective actions and modify RPN figure based on results.Before ImprovementAfter ImprovementRPNReduced RiskStep 9: Assess Results9.Assess Results33Effect Incomplete order, delay, customer dissatisfactionCause Multiple o

37、rders in processCurrent ControlsSeverity = 4 Occurrence = 4Detection = 2RPN = 4 x 4 x 2 = 32Step 9: Assess ResultsFailure ModeIncorrect Stock CheckStock Check is improved9.Assess Results34Process FMEA Roadmap1.Describe Process2.Define Functions3.Identify Potential Failure Modes4.Describe Effects of

38、Failure5.Determine Causes6.Current Controls7.Calculate Risk8.Take Action9.Assess ResultsFMEA PurposeRecognise and evaluate the potential failure modes and causes associated with a business process or manufacture of a product.Identify actions which could eliminate or reduce the chance of the potentia

39、l failure occurring.Document the analysis and changes made.36FMEA Form37FMEA Brainstorming (Measure Stage)38FMEA Risk Analysis (Analyze stage)39FMEA Action Planning (Analyze Stage)40FMEA Implement Action Plan (Improve Stage)41FMEA Verify (before project closure)42Workshop 2: Risk AssessmentTransfer

40、the failure modes, effects and causes identified in workshop 1 to the large FMEA form.Using the Severity rating scale, rate each of the failure mode effects and record the number in the appropriate column. Where there are several possible effects for a failure mode, take the worst case for the ratin

41、g. There should be only one severity rating for each failure mode.Using the Occurrence rating scale and your teams expertise, rate each of the potential causes of failure and record the numbers in the appropriate column.For the purpose of the exercise, assume there are no Current Controls (Detection

42、 rating = 11), calculate the Risk Priority Numbers (RPN) and record on the chart. There should be one RPN score for each cause listed on the FMEA form.For the top five RPNs, identify possible actions to reduce the RPN scores. Identify which of the categories (Severity, Occurrence, and Detection) wou

43、ld be reduced once the action has been completed.Prepare a short presentation to summarise your teams findings.43Implementing FMEAImproveTeam not an individualCross functional opportunity to improve communication and understandingInclude the processors (people who work in the process)Consider includ

44、ing the customer where appropriateWho Should Do FMEA ?4510 Keys To FMEA SuccessSupport by top & middle managementMotivated team membersCross functional representation on the teamTreat as “before the event not “after the factGenerate company specific rating scalesTreat as a living document-reflect latest revisionsExecute recommended actionsIntegration into