【正文】 因樹 Effects Tree/後果樹 Fire in Plant 工廠 起火 Operator Injury 員工受傷 Damaged Equip 設(shè)備損壞 Must Repair Vehicle 必需維修車輛 Poor Instruction 指導(dǎo)書 不足 Not Trained 未培訓(xùn) Operator Error 操作員 錯(cuò)誤 Board Error 電路板 錯(cuò)誤 Operator Tired 操作人員疲勞 Crossed Wire 交叉的電線 61 FMEA ? Process controls catch the defect before the product reaches the customer /程序控制當(dāng)在産品到達(dá)顧客前發(fā)現(xiàn)缺陷 ! ? There are three types of process controls 程序控制有三種類型 : (1) Prevent the cause of failure, or reduce the rate of occurrence 防止原因出現(xiàn)或降低其出現(xiàn)的可能性 (2) Detect the cause(s) of failure and lead to corrective actions 查明失效的原因並找出糾正措施 (3) Detect the failure mode(s) /檢測(cè)失效模式 Assign Currently used process controls to failure modes and causes 針對(duì)失效模式或原因列出現(xiàn)行的程序控制手段 62 FMEA ? Detection is an assessment of the probability that 探測(cè)度爲(wèi)下列事件發(fā)生的概率 ? A type 2 control can detect the cause and lead to corrective action 第 2類控制能夠發(fā)現(xiàn)原因並找到糾正措施 ? A type 3 control can detect a failure 第 3類控制能夠在不良品到達(dá)顧客前發(fā)現(xiàn)缺陷 ... before the product reaches the customer! ? Detection can also assess how effectively a type 1 control can prevent failure 第 1類控制能夠預(yù)防失效的有效程度 63 FMEA ? Aim for PREVENTION rather than detection 目的是 預(yù)防 而不是探測(cè) ? Begin with the highest RPN item 從 RPN高的專案開(kāi)始 – Don’t set an a prior “cutoff” value (. prior to beginning the FMEA) 勿預(yù)先設(shè)定“分?jǐn)?shù)線” (例如在開(kāi)始做 FMEA前 ) ? Give serious attention to items with Severity = 9 or 10 嚴(yán)重度＝ 9或 10時(shí)應(yīng)特別注意 64 FMEA ? What corrective action, if any, should be taken to reduce應(yīng)採(cǎi)取哪些措施以降低 – Severity (probably need a design change) 嚴(yán)重度（可能需修改産品設(shè)計(jì)） – Likelihood of occurrence 發(fā)生的可能性 – Detection rating/ 可探測(cè)度 ? You don39。t fet auxiliary functions as well a primary functions 主要功能和輔助功能都要考慮 ? Often, ponents work together to perform a function 經(jīng)常是幾個(gè)零件共同實(shí)現(xiàn)一個(gè)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(gè)要素的功能 41 FMEA ? A defect, flaw, or other unsatisfactory condition in the product that is caused by a design weakness 由於設(shè)計(jì)缺陷造成的產(chǎn)品缺陷 ,瑕疵或其它令人不滿意的情況 ? Typical Failure Modes: 典型的失效模式 Breaks Cracks 破碎 裂紋 Corrodes Sticks 腐蝕 粘結(jié) Deforms/melts 變形 /熔化 42 FMEA ? Start with the previous two steps: 從前両個(gè)步驟入手 : – Functions 功能 – Quality requirements 質(zhì)量要求 43 FMEA ? In your own descriptive words, write down the following scenarios， 用自己的語(yǔ)言描述下列假設(shè) ： Failure = No function， 失效 = 無(wú)功能 Failure = Not enough function， 失效 = 功能不足 Failure = Too much function， 失效 = 功能過(guò)強(qiáng) ? Similarly,同樣 ： Failure = No quality requirement 失效 = 未達(dá)到質(zhì)量要求 44 FMEA ? An effect can be ， 後果可能是 ： – 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 than one effect! 許多失效模式不止有一個(gè)後果 ！ ? Effects of failure often show up as a chain of events, from immediate effect to the ultimate effect on the customer 失效模式的後果經(jīng)常表現(xiàn)為對(duì)客戶的一連串的影響 ,包括直接的後果和最終的後果 45 FMEA Determine Potential Cause(s) of Each Failure Mode 確定每種失效模式的潛在原因 ? A cause of failure is a design weakness that leads to the failure mode 造成失效的原因是由於 設(shè)計(jì)缺陷 引起 – Inherent in the way the product was designed 是產(chǎn)品設(shè)計(jì)所固有的 – Relative to the usage of the product 與產(chǎn)品的使用方法有關(guān) ? Many failure modes have multiple causes! 許多失效模式有多個(gè)起因 ！ 46 FMEA If the design asis were to go into production. 如果依據(jù)現(xiàn)有設(shè)計(jì)進(jìn)行生產(chǎn)的話 ? Use historical data， 利用歷史資料 ? Take improvements into account， 參考已有的改進(jìn) ? Consider the lifespan of the product， 考慮產(chǎn)品的壽命 ? Use reliability models and parison 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(píng)估每種原因發(fā)生的可能性 47 FMEA ? There are three types of design controls: 設(shè)計(jì)控制有三種類型 ： (1) Those that prevent the cause of failure。 13 FMEA Rules of Design FMEA 設(shè)計(jì) 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(jì)工程師和項(xiàng)目小組的工具用來(lái)提高設(shè)計(jì)的前瞻性 (在問(wèn)題發(fā)生前 ) ? Used to established 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 用於確定重要安全特性 14 FMEA Purpose of Design FMEA 設(shè)計(jì) FMEA的用途 ? Establishes critical features that must be controlled in manufacturing to satisfy customer requirements 確定那些必須在生產(chǎn)中進(jìn)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(jì)中的不足和相應(yīng)的措施 ? Helps evaluate the risk of design changes 幫助評(píng)價(jià)設(shè)計(jì)變更的風(fēng)險(xiǎn) 15 FMEA Purpose of Design FMEA 設(shè)計(jì) FMEA的用途 ? Identifies process development needs 確定開(kāi)發(fā)工藝流程的需求 ? Dynamic document – documents design alternatives and associated risks 動(dòng)態(tài)的文件 – 記錄可選擇的設(shè)計(jì)方案和相應(yīng)的風(fēng)險(xiǎn) ? Establishes bases for manufacturing and quality control plan 建立製造和品質(zhì)控制計(jì)劃的基礎(chǔ) 16 FMEA Design FMEA Inputs and Outputs 設(shè)計(jì) FMEA的輸入和輸出 ? Product drawings 產(chǎn)品圖紙 ? Product models 產(chǎn)品模型 ? Product specification 產(chǎn)品規(guī)格 ? Identified Critical to Quality failures 確定的重要質(zhì)量特性 ? Actions to prevent the c