FMEA失效模式及其影響分析中英文(共63頁).ppt

1、12Describe FMEA principles and techniques. n描述描述FMEA的法則及技巧。的法則及技巧。Summarize the concepts, definitions, application options and relationships with other tools.摘要概念、定義、應用的選擇和其他工具的關(guān)聯(lián)。摘要概念、定義、應用的選擇和其他工具的關(guān)聯(lián)。Perform a FMEA執(zhí)行一個執(zhí)行一個FMEA。3FMEA: Failure Modes and Effects AnalysisFMEA is a systematic approach

2、used to examine potential failures and prevent their occurrence. It enhances our ability to predict problems and provides a system of ranking, or prioritization, so the most likely failure modes can be addressed. FMEA是用來檢查潛在失效和預防它再次發(fā)生的系統(tǒng)性方法.它增強了我們預測問題的能力,并提供了一個排序或區(qū)分優(yōu)先次序的系統(tǒng),因而使得最可能的失效模式得以確定.FMEA is g

3、enerally applied during the initial stages of a process or product design. Brainstorming is used to determine potential failure modes, their causes, their severity, and their likelihood of occurring. In Six Sigma, we apply FMEA to know failure modes. Our main interests are the cause and likelihood o

4、f occurrence, for which we have actual data and do not need to rely on brainstorming.FMEA通常應用在工藝及產(chǎn)品設計的初期，自由討論決定潛在失效的模式、原因、嚴重度及發(fā)生的可能性。在6S中，我們應用FMEA去了解失效的模式。我們主要感興趣的是原因及發(fā)生的可能性。FMEA is also a valuable tool for managing tasks during defect/failure reduction projects.FMEA也是一個在失效縮小的管理任務的有價值的工具。4lrecognize

5、 and evaluate the potential failure modes and causes associated with the designing and manufacturing of a new product or a change to an existing product.l認識和評估認識和評估新產(chǎn)品的設計和制造時或?qū)ΜF(xiàn)有產(chǎn)品做出改變時相關(guān)的潛在失效模式和原因lidentify actions which could eliminate or reduce the chance of the potential failure occurring,l確定確定消除

6、或減少潛在失效發(fā)生機會的行動ldocument the process.l使過程形成使過程形成文件文件FMEA is a systematic design evaluation procedurewhose purpose is to: 是系統(tǒng)的設計評估程序是系統(tǒng)的設計評估程序5Failure to perform a defined function執(zhí)行既定功能的失效Something occurring that you dont expect, or want發(fā)生了你不希望或不想要的事情Wrong application應用錯誤6lTo identify potential failu

7、re modes and rate the severity of their effectslTo identify critical characteristics and significant characteristicslTo rank potential design and process deficiencieslTo help all of us focus on eliminating product and process concerns and prevent problems from recurringlReduce the product developmen

8、t timing and cost7Developed in early 60s by NASA to “fail-proof” Apollo missions.Adopted in early 70s by US Navy .By late 80s, automotive industry had implemented FMEA and began requiring suppliers do the same. Liability costs were the main driving force.Used sporadically throughout industry during

9、1980s.Adopted by MSI in ? Six Sigma is the catalyst.8NASA used FMEA to identify Single Point Failures on Apollo project (SPF = no redundancy & loss of mission). How many did they find?420and we thought we had problems!9SYSTEM DESIGNPROCESSSystem FMEA is used to analyze systems and subsystems in

10、the early concept and design stages.Design FMEA is used to analyze products before they are released to productionProcess FMEA is used to analyze manufacturing, assembly and administrative processes10“Do the best you can with what you have”AS EARLY AS POSSIBLE!Guideline:11When new systems, products

11、and processes are being designedWhen existing designs and processes are being changedWhen carry-over designs or processes will be used in new applications or environmentsAfter completing a Problem Solving Study, to prevent recurrence of a problem12STARTCOMPLETESYSTEMAfter system functionsare defined

12、, beforespecific hardware isselectedWhen the project isturned over to designDESIGNAfter product functionsand design concepts aredefined but before thedesign is completeWhen final drawingsare releasedPROCESSWhen preliminarydrawings are availablebut before tooling designis completedWhen the productrea

13、ches end of life or isremoved fromproduction13Design StartDevelopmentProduction ReleaseProduction TimeNo of Engineering ChangesTraditional approachFMEA approach14Potential Failure Mode and Effects Analysis PFMEA #: Process Responsibility: Prepared By: Process Name: Affected Products:#ProcessFunction

14、(Step)Potential FailureModes (ProcessDefects)PotentialEffects ofFailures (KPOVs)SEVPotential Causes ofFailures (KPIVs)OCCCurrentProcessControlsDETR P NRecommendActionsWhat is theprocess stepWhat is thekey processinputIn what waydoes the keyinput go wrongHow severe is the effect to customerWhat cause

15、s thekey input to gowrongHow often does cause occurWhat arethe existingcontrols &procedures(inspection& test) thatprevent withthe cause orFailureModeHow well can you detect cause ot FMWhat arethe actionsforreducingtheoccurrenceof theCause, orimprovingDetection?Should haveactions onlyon highR

16、PNs oreasy fixes.15CPotentialOProcessPotentialPotentialSlCause(s)cFailureEffect(s) ofeaMechanism(s)cFunction ModeFailurevsof FailureusrPoor training3Fail to detect in the process ofincoming inspection2Misunderstanding of defectdefinition2OP 100 INCOMINGINSPECTION -PORT FITTING/Toverify ports madeto

17、printFail to identify damagedportPoor PrintbilityPoor gagePlacement Weldingprocess failureSealing processfailureFuction testin failure816Failure Mode Any way in which a process could fail to meet some measurable expectation.Effect Assuming a failure does occur, describe the effects. List separately

18、each main effect on both a downstream operation and the end user.Severity Using a scale provided, rate the seriousness of the effect. 10 represents worst case, 1 represents least severe.Causes This is the list of causes and/or potential causes of the failure mode.Occurrence This is a ranking, on a s

19、cale provided, of the likelihood of the failure occurring. 10 represents near certainty; 1 represents 6 sigma. In the case of a Six Sigma project, occurrence is generally derived from defect data.Current Controls All means of detecting the failure before product reaches the end user, are listed unde

20、r current controls.Detection The effectiveness of each current control method is rated on a provided scale from 1 to 10. A 10 implies the control will not detect the presence of a failure; a 1 suggests detection is nearly certain.17lThe potential failure mode is the manner in which the process could

21、 fail to perform its intended function. lThe failure mode for a particular operation could be a cause in a subsequent (downstream) operation or an effect associated with a potential failure in a previous (upstream) operation. FAILUREMODEEFFECTPREVIOUSOPERATIONCAUSENEXTOPERATION18 Process FMEA consid

22、ers process variability due to:OPERATORSET-UPMACHINEMETHODENVIRONMENTMEASUREMENT19uAssessment of the ability of the control to detect the failure before the item leaves the manufacturing area and ships to the customer.uCapability of all controls in the process to prevent escapesSPCProcess Capability

23、Gage R&RSamplingTestingDOE20SEVERITYAs it applies to the effects on the local system, next level, and end userOCCURRENCELikelihood that a specific cause will occur and result in a specific failure modeDETECTIONAbility of the current / proposed control mechanism to detect and identify the failure

24、 modeTypically, three items are scored:21RPN = O x S x D Occurrence x Severity x DetectionOSD xx= RPN22A 8 4 3 96B 4 8 3 96SAME RESULTFailure ModeSeverityOccurrenceEffectivenessRPN23EffectCriteria: Severity of Effect DefinedRankingHazardous:Without WarningMay endanger operator. Failure mode affects

25、safe vehicle operation and / orinvolves noncompliance with government regulation. Failure will occur WITHOUTwarning.10Hazardous: WithWarningMay endanger operator. Failure mode affects safe vehicle operation and / orinvolves noncompliance with government regulation. Failure will occur WITHwarning.9Ve

26、ry HighMajor disruption to production line. 100% of product may have to be scrapped.Vehicle / item inoperable, loss of primary function. Customer very dissatisfied.8HighMinor disruption to production line. Product may have to be sorted and a portion(less than 100%) scrapped. Vehicle operable, but at

27、 a reduced level ofperformance. Customer dissatisfied.7ModerateMinor disruption to production line. A portion (less than 100%) may have to bescrapped (no sorting). Vehicle / item operable, but some comfort / convenienceitem(s) inoperable. Customers experience discomfort.6LowMinor disruption to produ

28、ction line. 100% of product may have to be reworked.Vehicle / item operable, but some comfort / convenience item(s) operable atreduced level of performance. Customer experiences some dissatisfaction.5Very LowMinor disruption to production line. The product may have to be sorted and aportion (less th

29、an 100%) reworked. Fit / finish / squeak / rattle item does notconform. Defect noticed by most customers.4MinorMinor disruption to production line. A portion (less than 100%) of the product mayhave to be reworked on-line but out-of-station. Fit / finish / squeak / rattle itemdoes not conform. Defect

30、 noticed by average customers.3Very MinorMinor disruption to production line. A portion (less than 100%) of the product mayhave to be reworked on-line but in-station. Fit / finish / squeak / rattle item doesnot conform. Defect noticed by discriminating customers.2NoneNo effect.124Probability of Fail

31、urePossible Failure RatesCpkRankingVery High:1 in 2 0.3310Failure is almost inevitable1 in 30.339High: Generally associated withprocesses similar to previous1 in 80.518processes that have often failed1 in 200.677Moderate: Generally associatedwith processes similar to1 in 800.836previous processes wh

32、ich have1 in 4001.005experienced occasional failures,but not in major proportions1 in 2,0001.174Low: Isolated failures associatedwith similar processes1 in 15,0001.333Very Low: Only isolated failuresassociated with almost identicalprocesses1 in 150,0001.52Remote: Failure is unlikely. Nofailures ever

33、 associated withalmost identical processes1 in 1,500,0001.67125DetectionCriteria: Liklihood the existence of a defect will bedetected by test content before product advances tonext or subsequent processRankingAlmost ImpossibleTest content detects 80 % of failures10Very RemoteTest content must detect

34、 80 % of failures9RemoteTest content must detect 82.5 % of failures8Very LowTest content must detect 85 % of failures7LowTest content must detect 87.5 % of failures6ModerateTest content must detect 90 % of failures5Moderately HighTest content must detect 92.5 % of failures4HighTest content must dete

35、ct 95 % of failures3Very HighTest content must detect 97.5 % of failures2Almost CertainTest content must detect 99.5 % of failures126It is conducted on a timely basisandIt is applied by a product teamandIts results are documented27Involve new technology Have changed from previous Are chronically in

36、trouble Have a high degree of operator control Have a high degree of variationChoose designs or processes which . . .Involve new technologyHave changed from previousAre chronically in troubleHave a high degree of operator controlHave a high degree of variationChoose designs or processes which.28Manu

37、facturing EngineerBuyerProcessOperatorProcess KnowledgePrevious ExperiencePast ProblemsChronic ProblemsReliabilityEngineerProcess Functions, Potential Failure ModesEffects, Causes, Current ControlsAction PriorityActions to Eliminate or Reduce Failure ModeWarranty Claims291. Develop a StrategyS S T T

38、 9 9 1 1 2 2 6 6 0 0 A AD D R R I IV V E EB B A A S S E E S S U U B BS S Y Y S S T T E E M M & & F F I IR R M M W WA A R R E E C C O O V V E E R RM M E E D D I IA AD D I IS S C C P P A A C C K KF F I IN N A A L L A A R R M MA A R R M M S S U U B BA A R R M M C C O O I IL LB B O O B B B B I I

39、N NR R O O T T . . A A R R M MS S P P . . F F L L E E X XS S P P I IN N D D L L E ES S T T A A T T O O R RR R O O T T O O R RH H D D A A A A S S S S E E M M B B L L Y YB B A A S S E E D D E E C C K KR R E E C C I IR R F F I IL L T T E E R RB B R R E E A A T T H H . . F F I IL L T T E E R RL L A A B

40、B E E L L S SP P C C B B A A S S S S E E M M B B L L Y YD D I IS S C C C C L L A A M M P PB B A A L L . . W WT TS S P P A A C C E E R R S SM M A A G G A A S S S S Y YL L A A T T C C H HA A R R M M S S U U B BA A R R M M S S U U B BB B A A S S E E D D E E C C K KD D A A M M P P E E R RS S E E A A L L

41、M M O O T T O O R R P P O O L L E E S S , , P P O O L L E E S S P P A A C C E E R RTe a m s w ill b e e sta b lishe d to e va lua te the a p p lica tio n o f F M E A in a re a s sho w n b y the sha d ing o n the fo llo w ing d ia g ra m . E a ch F M E A Te a m und e r the d ire ctio n o f the F M E

42、A F a cilita to r w ill:- E S TA B L IS H a stra te g y fo cusing o n ne w te chno lo g y, p a st issue s, ne w o r re d e sig ne d co m p o ne nts, b o th fro m the p ro d uct (d e sig n) a nd p ro ce ss p e rsp e ctive s.- P R E P A R E a D e sig n a nd a P ro ce ss F M E A fo r the se le cte d co

43、 m p o ne nts o r sub a sse m b lie s.- D E TE R M IN E functio ns, p o te ntia l fa ilure m o d e s, e ffe cts, ca use s, a nd ve rifica tio n a ctivitie s p la nne d o r in-p la ce . - R E C O M M E N D co rre ctive a ctio ns to the p ro d uct te a m .F IR S T P R IO R IT YS E C O N D P R IO R IT

44、YT H IR D P R IO R IT Y301. Develop a Strategy2. Review the design /process EFFECTCAUSES311. Develop a Strategy2. Review the design /process3. List functionsDevelop a StrategyReview the design/processList functions321. Develop a Strategy2. Review the design /process3. List functions4. Brainstorm pot

45、ential failure modesBasic Steps:1. Develop a strategy2. Review the design/process3. List functions4. Brainstorm potential failure modes331. Develop a Strategy2. Review the design /process3. List functions4. Brainstorm potential failure modes5. Organize potential failure modestopictopicAffinity Diagr

46、am341. Develop a Strategy2. Review the design /process3. List functions4. Brainstorm potential failure modes5. Organize potential failure modes6. Analyze potential failure modes351. Develop a Strategy2. Review the design /process3. List functions4. Brainstorm potential failure modes5. Organize poten

47、tial failure modes6. Analyze potential failure modes7. Establish risk priorityVITALFEWTRIVIALMANY361. Develop a Strategy2. Review the design /process3. List functions4. Brainstorm potential failure modes5. Organize potential failure modes6. Analyze potential failure modes7. Establish risk priority8.

48、 Take action to reduce risk371. Develop a Strategy2. Review the design /process3. List functions4. Brainstorm potential failure modes5. Organize potential failure modes6. Analyze potential failure modes7. Establish risk priority8. Take action to reduce risk9. Calculate resulting RPNsO*S*D=RPN381. De

49、velop a Strategy2. Review the design /process3. List functions4. Brainstorm potential failure modes5. Organize potential failure modes6. Analyze potential failure modes7. Establish risk priority8. Take action to reduce risk9. Calculate resulting RPNs10. Follow up39IFTHENHOW DOI KNOW?CAUSEFAILURE MOD

50、EEFFECT40The design or process must be improved based on the results of the FMEA study.A well-developed FMEA will be of limited value without positive and effective corrective actions.41Describe FMEA principles and techniques. Summarize the concepts, definitions, application options and relationship

51、s with other tools.Perform a FMEA42Describe FMEA principles and techniques. Summarize the concepts, definitions, application options and relationships with other tools.Perform a FMEA4344Eyelash Learning CurveABILITY TODO JOBTIMEOLD EMPLOYEE LEAVESWITH KNOWLEDGENEW EMPLOYEE BEGINS There is no organiz

52、ational memory to allow people to start where their predecessors left off Nothing in place to capture the new or improved methods that produce results45ABILITY TODO JOBTIMENEW EMPLOYEE COMES ONAND PICKS UP ALMOST WHEREPREVIOUS EMPLOYEE LEFT OFF Organization continues to advance its knowledge by pres

53、erving the lessons each learns Rapid learning = less waste, less complexity, higher customer value, lower costs46Two key ingredients:1. Having best known methods documented2. Training people on what those methods areWho to train?lNew employeeslManagerslExperienced employeesSix Sigma47Advantages: 優(yōu)點優(yōu)

54、點lCustomer progress is more visible and can be tracked over time 顧客進步更可見而且可以隨時間跟蹤顧客進步更可見而且可以隨時間跟蹤lCapture and share lessons learned吸取和分享教訓吸取和分享教訓lSystem itself does not become a source of variation系統(tǒng)自身不會成為變異的來源系統(tǒng)自身不會成為變異的來源l Leads to efficient practices 導致有效率的實踐導致有效率的實踐 48Disadvantages: 缺點缺點lStifle

55、creativity and lead to stagnation 抑制創(chuàng)造力導致停滯不前抑制創(chuàng)造力導致停滯不前l(fā)Interfere with customer focus 干涉客戶的焦點干涉客戶的焦點lAdd bureaucracy and red tape 助長官僚作風助長官僚作風lMake work inflexible and boring 使工作欠缺靈活性，使人容易感到厭煩使工作欠缺靈活性，使人容易感到厭煩lOnly describe the minimal acceptable output只描述最小的可接受輸出只描述最小的可接受輸出49The difficulty we face

56、 is . . . .the arguments for and against standardization are both true 公說公有理，婆說婆有理公說公有理，婆說婆有理To achieve a balance, develop standards judiciously - where it matters the mostWhen effectively managed, standards provide the foundation for improvement 50Companies that use standardization effectively oper

57、ate very differently:lThe company knows why it is developing standards and how they contribute to its overall purposelManagement uses best-known methods themselves and strongly supports and checks usagelEmployees understand how different facets of their work affect the products and services lEmploye

58、es know which elements/functions are critical to producing high-quality output51Leverage Point: A place where a little change has a great impact 支點：小小的變化就能有巨大的影響的地方。支點：小小的變化就能有巨大的影響的地方。三兩撥千斤？三兩撥千斤？“ . every job, every process, has within it high-leverage points that we must standardize if we want to

59、 achieve consistently high performance, and low-leverage points where standardization is superfluous, serving only to restrict flexibility.”52“Knowledge about what is not important is almost as valuable as knowledge about what is important. It frees our attention to better focus on the few things th

60、at make a difference.” “This kind of flexibility shows up in all jobs.” “As a rule of thumb, keep the degree of standardization as low as possible but do not neglect any leverage points.” 53Knowing the leverage points is critical for determining priorities and strategies for improvementVital FewTrivial ManyPareto Princip