失效模式分析(1)ppt課件

1、1An analytical tool for identifying Potential Failures in a product or process so that corrective action can be taken before the failures can reach the customer.FMEA是一種識別產(chǎn)品或過程的潛在失效,以便在這些失效影響客戶之前 採取措施的分析工具2An FMEA is a Structured Approach to:FMEA是結(jié)構(gòu)式的方法 Identifying the ways in which a design or proce

2、ss can fail to meet the critical customer requirements識別設(shè)計或過程能夠以何種方式失效而不能滿足客戶重要需求 Estimating the risk of specific causes with regard to these failures估計產(chǎn)生這些失效的特殊緣由的風(fēng)險 Evaluating the current controls for preventing these failures評估現(xiàn)有控制手段對這些失效的預(yù)防 Prioritizing the actions that must be taken to improve

3、the design or the process給那些用以改進設(shè)計和過程的措施排序3FMEA History 歷史 First used in the 1960s during the Apollo Moon Missions.最早被用於上世紀六十年代的阿波羅登月計劃. In 1974 MIL-STD-1629 was developed by the Navy for using FMEAs.1974年海軍為FMEA的應(yīng)用制定了MIL-STD-1629. In the late 1970, adapted by the auto industry in response to higher

4、 liability costs and higher quality demands by customers.在二十世紀七十年代末, 為滿足客戶更高的責(zé)任本錢和質(zhì)量需求而被用於自動化工業(yè)中.4FMEA is proactive, not reactive. Dont wait for the customer to complain if you can avoid it!FMEA是預(yù)防性 的，不是反應(yīng)性的。應(yīng)當儘量防止失效，而不是等著顧客提出申訴！ 5FMEA reduces the chance that a customer will see a failureFMEA通過以下措施減

5、少顧客遇到失效的情況:By defining failure in terms of what the customer wants and expects.針對顧客的要求和期望確定失效By showing where measures need to be taken to prevent failure.指出爲了防止失效，需求在哪方面採取措施 6Types of FMEAs 類型Design used to analyze product designs before they are released to production設(shè)計 - 用於在產(chǎn)品投產(chǎn)前對設(shè)計的分析 Process us

6、ed to analyze manufacturing processes過程 - 用於分析製程 System used to analyze systems in the early concept and design stages系統(tǒng) 用於分析早期的概念和設(shè)計階段的系統(tǒng)7Summary 概要Identifies known and potential failure modes;識別知和潛在的失效方式Identifies the causes and effects of each failure mode;識別每一種失效方式的緣由和後果Prioritizes the failure m

7、odes (using the RPN); 利用風(fēng)險序數(shù) RPN給失效方式排序Should initiate corrective action where needed.必要時提出糾正措施8Timing of an FMEAFMEA的時機 FMEAs should be initiated when preliminary drawings of the design or process are available當初步的設(shè)計圖紙和工藝被制定出來時應(yīng)開始做FMEA Updated as identified issues are resolved當被發(fā)現(xiàn)的問題解決後要更新FMEA Can

8、be used on existing products to improve quality可用於現(xiàn)有的產(chǎn)品以提高質(zhì)量9System系統(tǒng)Wiring harness 線束Electronic module電控模塊Assembly總成System FMEA treats system as a“functional schematic系統(tǒng)FMEA從“功能關(guān)係圖入手來考慮SFMEA10An analytical tool used to identify system-level failure modes, and identify corrective actions to be taken

9、.是一種分析工具用來識別系統(tǒng)失效方式11It is similar to a Design FMEA, but focuses on the circuit schematic instead of physical failure of components.同DFMEA相類似, 系統(tǒng)FMEA側(cè)重於回路設(shè)計而不是元件的物理失效。Take electrical systems as examples.以電氣系統(tǒng)為例。12Example:舉例：Failure mode at electrical system level 電氣系統(tǒng)失效方式Open circuit at ckt A回路A出現(xiàn)開路C

10、ause: 緣由：Terminal unseated端子脫出Terminal unseated becomes a failure mode at the component level.端子脫出 是電氣元件的失效方式。13Rules of Design FMEA設(shè)計FMEA規(guī)則 Tool for design engineers and project team to improve the design in a preemptive manner (before failure occur)是設(shè)計工程師和項目小組的工具用來提高設(shè)計的前瞻性(在問題發(fā)生前) Used to establis

11、hed Critical to Quality features that effect the performance of the product用與那些影響產(chǎn)品性能的重要質(zhì)量特性 Used to establish Critical to Life features that effect the life of the product用於確定影響產(chǎn)品壽命的重要壽命特性 Used to establish Critical to safety features用於確定重要平安特性14Purpose of Design FMEA設(shè)計FMEA的用途Establishes critical f

12、eatures that must be controlled in manufacturing to satisfy customer requirements確定那些必須在生產(chǎn)中進行控制的特性以滿足客戶要求 Identifies deficiencies in the product design and associated action items找出產(chǎn)品設(shè)計中的缺乏和相應(yīng)的措施 Helps evaluate the risk of design changes幫助評價設(shè)計變更的風(fēng)險15Purpose of Design FMEA設(shè)計FMEA的用途 Identifies process

13、 development needs確定開發(fā)工藝流程的需求 Dynamic document documents design alternatives and associated risks動態(tài)的文件 記錄可選擇的設(shè)計方案和相應(yīng)的風(fēng)險 Establishes bases for manufacturing and quality control plan建立製造和品質(zhì)控制計劃的基礎(chǔ)16Design FMEA Inputs and Outputs 設(shè)計FMEA的輸入和輸出 Product drawings產(chǎn)品圖紙 Product models產(chǎn)品模型 Product specificatio

14、n產(chǎn)品規(guī)格 Identified Critical toQuality failures確定的重要質(zhì)量特性 Actions to prevent the causes of failures防止失效緣由的措施 Actions to detect failure modes發(fā)現(xiàn)失效方式的措施 History of actions and Responsibilities措施和責(zé)任人的記錄17Design 設(shè)計Components 元件Elements設(shè)計要素Design FMEA looks at physical failure modes of components and design e

15、lements設(shè)計FMEA著眼于元件及設(shè)計要素 的物理失效方式DFMEA18Rules of Process FMEA過程FMEA規(guī)則 Tool for process engineers and project team to improve the manufacturing process in a preemptive manner 是工藝工程師和項目小組的工具,用來提高製造工藝的前瞻性 Used to prioritize actions to ensure attention to critical processes that effect customers用與區(qū)分先後順序以確

16、保那些影響客戶的重要工藝Used to document process improvements用於工藝改進 Dynamic document for continuous improvement持續(xù)改進的動態(tài)文件19Purpose of Process FMEA過程FMEA的用途 Assists in the analysis of new manufacturing process幫助分析新的製造工藝 Establishes the bases for manufacturing process instructions and control sheets建立製造工藝文件和控制文件的基

17、礎(chǔ) Identifies new manufacturing process needs確定新製造工藝的需求 Helps evaluate the risk of process changes幫助評估工藝更改的風(fēng)險20Process 過程Manufacturing 制造Assembling裝配Process FMEA looks at product failures caused by the process failing to meet requirements過程FMEA著眼于因加工過程不符合要求所呵斥的產(chǎn)品 失效PFMEA21FMEA Team 小組 Team approach i

18、s necessary.需求團隊的方式 Responsible for Design FMEA Design Engineer設(shè)計工程師負責(zé)設(shè)計FMEA Responsible for Process FMEA Manufacturing Engineer製造工程師負責(zé)過程FMEA Recommended representatives:推薦人選:Design / 設(shè)計Manufacturing Engineers / 製造工程師Quality Engineers / 質(zhì)量工程師Reliability / 可靠性Materials / 原資料Suppliers / 供應(yīng)商22Definitio

19、n of Terms 術(shù)語Failure Mode The way in which a specific input requirement fails and if not detected, corrected or removed will cause an Effect to occur.失效方式 一個特殊的輸入要求失敗的方式或者由於未被發(fā)覺,糾正或消除而帶來的後果 Effect Impact on customer requirements 後果 對客戶要求的影響23Definition of Terms 術(shù)語Cause Source(s) of process variation

20、 that causes the Failure Mode to occur.緣由 呵斥失效方式發(fā)生的過程變差的來源 Current Control (proposed controls)當前的控制 (建議的控制)Design elements that ensure function確保功能的設(shè)計要素Mistake proofing, automated controls, set up instructions, gauges防錯,自動化控制,機器設(shè)定指導(dǎo)書,量具Audits, checklists, inspections, PM, etc.稽核,檢查表,檢驗,設(shè)備維護,等24Linki

21、ng Failure Modes to Effects失效方式和後果之間的聯(lián)繫Failure Mode 1Failure Mode 2Effect 1Failure Mode 1Effect 2Effect 1Failure Mode 1Failure Mode 2Effect 1Note that the relationship between the Failure Mode and Effect is not always 1-to-1 請留意失效方式和後果之間的關(guān)係不總是一對一Effect 225Risk Priority Number 風(fēng)險序數(shù) The output of a FM

22、EA is the “Risk of Priority Number - RPN一個FMEA的輸出是“風(fēng)險序數(shù)-RPN The RPN is a calculated number based on information provided regardingRPN是根據(jù)下面的資料計算出來的 The potential failure modes,潛在失效方式The effects, and後果The current or planned ability to detect the failure before it reaches the customer現(xiàn)有的和已計劃的才干可以在影響客戶前

23、覺察失效26Risk Priority Number 風(fēng)險序數(shù) It is calculated as the product of three quantitative rating 它是用三個級數(shù)計算出來的RPN = Severity * Occurrence * Detection風(fēng)險序數(shù) = 嚴重度 * 發(fā)生頻度 * 探測度 The RPN is not sacredRPN不是神聖的 Scaling for Severity, Occurrence, and Detection are locally developed嚴重度,發(fā)生頻度,探測度的尺度由本人制定 Other catego

24、ries may be added to suit need根據(jù)需求可以加上其他類型 High Risk Priority Numbers are significant to the success of the product design - actions must be taken to prevent failures高風(fēng)險序數(shù)對產(chǎn)品設(shè)計的勝利來講很重要 - 需求採取措施來防止失效27Definition of RPN Terms RPN術(shù)語Severity (of effect) Importance to customer, may involve function, safe

25、ty, reliability, or life of product (1= not severe, 10 = very severe)嚴重度(後果的) 對客戶的重要程度, 可包括功能,平安,可靠性, 產(chǎn)品壽命等方面. (1=不嚴重, 10=很嚴重) Occurrence (of cause) Frequency with which a given Cause may occur (1= not likely to occur, 10= very likely to occur)發(fā)生頻度 (緣由的) 一個特定的緣由能夠發(fā)生的頻度 (1= 不能夠發(fā)生, 10= 很能夠發(fā)生)Detection

26、 (Capability of current or planned Controls) Ability to detect the cause (1= likely to be detected, 10= not likely to be detected)探測度 (現(xiàn)有的或已計劃的控制才干) 覺察緣由的才干 (1= 有能夠發(fā)覺, 10= 不能夠發(fā)覺)28Rating Scales 評分尺度Rating得分 Degree of Severity/ 嚴重程度 1Customer will not notice the adverse effect or it is insignificant/

27、客戶不會注意到或該不利後果不重要 2Customer will probably experience slight annoyance/可能對客戶有輕微的影響3Customer will experience annoyance due to the slight degradation of performance/由於輕微的性能下降可能給客戶帶來麻煩 4Customer dissatisfaction due to reduced performance/由於性能下降使客戶不滿意 5Customer is made uncomfortable or their productivity

28、is reduced by the continued degradation of the effect/客戶不滿意或受持續(xù)降級的影響使他們的生產(chǎn)力降低 6Warranty repair or significant manufacturing or assembly complain/保修或者重大的製造或組裝的投訴 7High degree of customer dissatisfaction due to component failure without complete loss of function. Productivity impacted by high scrap or

29、 rework levels/零件雖未完全失去功能但引起客戶較大的不滿;由於高報廢,高返工率影響生產(chǎn)力 8Very high degree of customer dissatisfaction due to the loss of function without a negative impact on safety or government regulation/由於零件喪失功能而引起客戶極大不滿但尚未違反安全或國家規(guī)定 9Customer endangered due to adverse effect on safe system performance with warning

30、before failure or violation of governmental regulations/安全系統(tǒng)的不利影響使得客戶處於危險當中但在失效前有警告或違反國家規(guī)定 10Customer endangered due to adverse effect on safe system performance without warning before failure or violation of governmental regulations/安全系統(tǒng)的不利影響使得客戶處於危險當中而且失效前沒有警告或違反國家規(guī)定 29Rating Scales 評分尺度Rating得分 L

31、ikelihood of Occurrence/ 發(fā)生的可能性1Likelihood of occurrence is remote/ 發(fā)生的可能性極小2Low failure rate with support documentation/ 有書面證據(jù)證明發(fā)生的可能性很低3Low failure rate without support documentation/發(fā)生的可能性很低但沒有書面證據(jù)證明4Occasional failure/ 偶爾失效5Relatively Moderate failure rate with supporting documentation/有書面證據(jù)證明中等

32、的失效可能性6Moderate failure rate without supporting documentation/沒有書面證據(jù)證明中等的失效可能性7Relatively high failure rate with supporting documentation/有書面證據(jù)證明高度的失效可能性8Relatively high failure rate without supporting documentation/沒有書面證據(jù)證明高度的失效可能性9Failure is almost certain based on warranty data or significant tes

33、ting/ 根據(jù)保修數(shù)據(jù)或重要試驗幾乎可以肯定失效會發(fā)生10Assure of Failure based on warranty data or significant testing/ 根據(jù)保修數(shù)據(jù)或重要試驗可以肯定失效會發(fā)生30Rating Scales 評分尺度Rating得分 Ability of Detect/ 可探測度 1Sure that the potential failure will be found or prevented before reaching the next customer/確定潛在失效可以在到達下一個客戶前被發(fā)現(xiàn)或預(yù)防2Almost certain

34、 that the potential failure will be found or prevented before reaching the next customer/幾乎可以肯定潛在失效可以在到達下一個客戶前被發(fā)現(xiàn)或預(yù)防3Low likelihood that the potential failure will reach the next customer/潛在的失效到達下一個客戶的可能性很低4Controls may detect or prevent the potential failure from reaching the next customer/控制手段可以防止

35、潛在失效到達下一個客戶5Moderate likelihood that the potential failure will reach the next customer/潛在的失效到達下一個客戶的可能性中等6Controls are likely to detect or prevent the potential failure from reaching the next customer/控制手段不太可能防止?jié)撛谑У竭_下一個客戶7Poor likelihood that the potential failure will be detected or prevented bef

36、ore reaching the next customer/在潛在失效到達下一個客戶前發(fā)現(xiàn)或預(yù)防的可能性較低8Very poor likelihood that the potential failure will be detected or prevented before reaching the next customer/在潛在失效到達下一個客戶前發(fā)現(xiàn)或預(yù)防的可能性非常低9Current controls probably will not detect the potential failure/現(xiàn)有控制手段可能探測不到潛在失效10Absolute certainly that

37、the current controls will not detect the potential failure/完全肯定現(xiàn)有的控制手段無法探測潛在失效31Examples of Occurrence scale發(fā)生率評分的例子Scale Value分值Occurrences perWeek週Day日Shift班Hour小時107001003349500712438350501727200291016100145157511445072325412711132Examples of Detection scale探測度評分的例子Scale Value/分值Percent of potent

38、ial failures prevented預(yù)防潛在失效的比率190%280%370%460%550%640%730%820%910%100%33ProcessStep/InputPotential Failure ModePotential Failure EffectsSEVPotential CausesOCCCurrent ControlsDETRPNActions Recommended0000000000000000What is the input?輸入是甚麼?What can go wrong with the input?輸入會出甚麼錯?What is theEffect o

39、nthe output?輸出的後果是甚麼?What arethe causes?緣由是甚麼?How well?程度如何?How canthis be found?怎樣才可以發(fā)現(xiàn)?How often?頻繁程度What can be done?可以做甚麼?How well?程度如何?34FMEA FAILURE MODE EFFECTS ANALYSISProduct:ProcessStep/InputPotential Failure ModePotential Failure EffectsSEVPotential CausesOCCCurrent ControlsDETRPNActions

40、RecommendedResponsibilityWhat is the step or input under investigation?In what way does the key input go wrong?What is the impact on the key output variable (customer requirement or internal requirement)How severe is the impact on the customer?What causes the key output to go wrong?How often does ca

41、use of failure mode happen?What are the existing controls and procedures (inspection and testing) that prevent either the cause or the failure mode? Include shop operating procedure number How well can the failure mode of cause be detected?RPN = SEV * OCC * DETWhat are the actions for reducing the o

42、ccurrence of the cause or improving detection? Should have actions on all high RPN numbers.Who is responsible for implementing the recommended actions?000035FMEA Model 方式Prevention/預(yù)防Prevention/預(yù)防Prevention/預(yù)防Cause/緣由Effect/後果Failure Mode/失效方式Controls/控制Material or process input/原料或過程輸入Process Step/

43、工序External customer or downstream process step/外部客戶或下一工序36General Steps in the DFMEA/普通步驟 Select design FMEA team 組建設(shè)計FMEA小組List customer requirements 列出客戶的要求 For each customer requirement list the key design elements that satisfy the customer requirements 針對客戶的每一個要求列出滿足該要求的關(guān)鍵設(shè)計要素 For each key desig

44、n element list ways that the design element could vary, Potential Failure Modes 列出每一個關(guān)鍵設(shè)計要素的變化,潛在的失效方式 List Effects of each Failure mode on the customer requirement 列出每個失效方式的對客戶要求的影響 List Causes for each failure Mode 列出失效方式的緣由37General Steps in the DFMEA/普通步驟 List current controls for each cause 列出每

45、個緣由的現(xiàn)有控制手段 Assign Severity, Occurrence, and Detection ratings to each cause給每個緣由的嚴重度,頻度,可探測度評分 Calculate RPNs 計算風(fēng)險序數(shù) Recommend actions to reduce high RPNs 提出降低風(fēng)險序數(shù)的措施 Take appropriate action 採取適當?shù)拇胧?Recalculate RPNs 重新計算風(fēng)險序數(shù)38A schematic representation, with 一種圖示法, 其中 Components (or features) shown

46、as blocks, 用方塊表示各元件(或特性)Interactions between components shown as lines, 用直線表示各元件之間的關(guān)係At the appropriate level of detail詳細到恰當?shù)某潭?Develop a Functional Block Diagram of The Product繪制產(chǎn)品功能結(jié)構(gòu)圖39Component元件Component元件Component元件Component元件Component元件Component元件Block Diagram 結(jié)構(gòu)圖Examples例如40Dont forget auxil

47、iary functions as well a primary functions主要功能和輔助功能都要考慮Often, components work together to perform a function 經(jīng)常是幾個零件共同實現(xiàn)一個功能Hint: Use the Block Diagram!提示: 利用結(jié)構(gòu)圖List The Function(s) of Each Component列出每個要素的功能41A defect, flaw, or other unsatisfactory condition in the product that is caused by a desig

48、n weakness 由於設(shè)計缺陷呵斥的產(chǎn)品缺陷,瑕疵或其它令人不滿意的情況Typical Failure Modes:典型的失效方式- Breaks - Cracks 破碎 裂紋- Corrodes - Sticks 腐蝕 粘結(jié)- Deforms/melts 變形/熔化42Start with the previous two steps: 從前両個步驟入手: Functions 功能Quality requirements質(zhì)量要求43In your own descriptive words, write down the following scenarios，用本人的語言描畫以下假設(shè)：

49、Failure = No function， 失效 = 無功能Failure = Not enough function， 失效 = 功能缺乏Failure = Too much function， 失效 = 功能過強Similarly,同樣：Failure = No quality requirement失效 = 未達到質(zhì)量要求44An effect can be ，後果能夠是：Complete loss of function，功能完全喪失Degradation of performance or quality性能或質(zhì)量下降Many failure modes have more tha

50、n one effect!許多失效方式不止有一個後果！Effects of failure often show up as a chain of events, from immediate effect to the ultimate effect on the customer失效方式的後果經(jīng)常表現(xiàn)為對客戶的一連串的影響,包括直接的後果和最終的後果45Determine Potential Cause(s) of Each Failure Mode確定每種失效方式的潛在緣由A cause of failure is a design weakness that leads to the

51、failure mode呵斥失效的緣由是由於設(shè)計缺陷 引起Inherent in the way the product was designed是產(chǎn)品設(shè)計所固有的Relative to the usage of the product與產(chǎn)品的運用方法有關(guān)Many failure modes have multiple causes! 許多失效方式有多個原因！46If the design as-is were to go into production.假設(shè)依據(jù)現(xiàn)有設(shè)計進行生產(chǎn)的話Use historical data，利用歷史資料Take improvements into account

52、，參考已有的改進Consider the lifespan of the product，考慮產(chǎn)品的壽命Use reliability models and comparison with similar products，利用可靠性模型並與類似產(chǎn)品比較Assess The Likelihood of Occurrence of Each Cause評估每種緣由發(fā)生的能夠性47There are three types of design controls:設(shè)計控制有三種類型：(1) Those that prevent the cause of failure; 預(yù)防產(chǎn)生失效的緣由；(2)

53、Those that detect the cause(s) of failure; 覺察產(chǎn)生失效的緣由；(3) Those that detect the failure mode(s) 檢測失效方式48Detection Rating (D): 探測度評分9-10Remote chance of detecting failure察明失效的能夠性極小7-8Very low chance，能夠性很小5-6Low to moderate chance，能夠性不大2-4Good chance，能夠性較大 1Will almost certainly detect failure(If it pa

54、sses this, it will not fail)失效幾乎都可以被査到(假設(shè)通過這樣的檢查就不會有失效)49To reduce severity - design change to control the effect降低嚴重度 通過設(shè)計更改來控制後果To reduce occurrence - design change to control the cause減少發(fā)生頻度 -通過設(shè)計更改來控制緣由To improve detection - improved testing or simulation methods增強探測度 改進測試和模擬方法Special Attention

55、if Severity = 9 or 10當嚴重度為9或10時要特別留意50General Steps in the PFMEA/普通步驟 Select process FMEA team 組建過程FMEA小組 Develop a Process Map and identify all process steps 做一個流程圖確定過程的一切步驟 List all the Key Process Outputs to satisfy internal and external customer requirement 列出一切的滿足內(nèi)部和外部客戶要求的關(guān)鍵過程輸出 For each proce

56、ss step, list Key Process Input Variables 列出每一步的關(guān)鍵過程輸入變量 For the Process Define C&E matrix relating Key Outputs to Key Process Input Variable 用因果圖分析關(guān)鍵過程輸入和關(guān)鍵輸出的聯(lián)繫 Rank the KPIVs according to importance 根據(jù)重要程度給關(guān)鍵過程輸入變量分級 Start the process FMEA 開始做過程FMEA51General Steps in the PFMEA/普通步驟 For each proce

57、ss input, list ways that it can vary (failure Modes) and identify associated effects 對每一個過程的輸入,列出其能夠的變化和相應(yīng)的後果 List all Causes for each Failure Mode 列出失效方式的一切緣由 List the current Controls for each cause 列出每個緣由的現(xiàn)有控制手段 Assign Severity, Occurrence, and Detection ratings to each cause 給每個緣由的嚴重度,頻度,可探測度評分

58、Calculate the RPN for each potential Failure Mode scenario 計算每個潛在失效方式的風(fēng)險序數(shù) Determine recommended actions to reduce High RPNs 提出降低風(fēng)險序數(shù)的措施 Take appropriate actions 採取適當?shù)拇胧?Recalculate RPNs 重新計算風(fēng)險序數(shù)52Use the Process Flow Diagram format 適用流程圖的格式Identifies fabricate, move, store and inspect operations 識別

59、四種作業(yè)類型,製造,移動,儲存,檢驗Identifies Key Characteristics識別關(guān)鍵特性A function is what the operation does 功能系指該操作所起的作用 State the function as /闡明功能為：Verb + Object + Qualifier 動詞+賓語+修飾詞 Mold part /成型零件 Crimp terminal onto cable /電線上壓接端子 Form bend in part /零件彎曲成形53A customer want or desire顧客的希望或要求 Could seriously af

60、fect customer perception有能夠嚴重影響顧客的看法 Could lead to a customer complaint有能夠?qū)е骂櫩屯对V A defect, flaw, or other unsatisfactory condition in the product that occurs when the process fails to meet the process requirements由於過程未達到要求而導(dǎo)致的産品缺陷、瑕疵等不良狀態(tài) Failure modes should be written in terms of the condition of