【正文】 預(yù)防產(chǎn)生失效的原因 ； (2) Those that detect the cause(s) of failure。 識(shí)別已知和潛在的失效模式 – Identifies the causes and effects of each failure mode。 識(shí)別每一種失效模式的原因和後果 – Prioritizes the failure modes (using the RPN)。 覺察產(chǎn)生失效的原因 ； (3) Those that detect the failure mode(s) 檢測(cè)失效模式 48 FMEA Detection Rating (D): 探測(cè)度評(píng)分 910 Remote chance of detecting failure 察明失效的可能性極小 78 Very low chance， 可能性很小 56 Low to moderate chance， 可能性不大 24 Good chance， 可能性較大 1 Will almost certainly detect failure (If it passes this, it will not fail) 失效幾乎都可以被査到 (如果通過這樣的 檢查就不會(huì)有失效 ) 49 FMEA ? To reduce severity design change to control the effect 降低嚴(yán)重度 – 通過設(shè)計(jì)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(jì)更改來控制原因 ? To improve detection improved testing or simulation methods 增強(qiáng)探測(cè)度 – 改進(jìn)測(cè)試和模擬方法 ? Special Attention if Severity = 9 or 10 當(dāng)嚴(yán)重度為 9或 10時(shí)要特別注意 50 FMEA General Steps in the PFMEA/一般步驟 ? Select process FMEA team 組建過程 FMEA小組 ? Develop a Process Map and identify all process steps 做一個(gè)流程圖確定過程的所有步驟 ? List all the Key Process Outputs to satisfy internal and external customer requirement 列出所有的滿足內(nèi)部和外部客戶要求的關(guān)鍵過程輸出 ? For each process 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 CE 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(jí) ? Start the process FMEA 開始做過程 FMEA 51 FMEA General Steps in the PFMEA/一般步驟 ? For each process input, list ways that it can vary (failure Modes) and identify associated effects 對(duì)每一個(gè)過程的輸入 ,列出其可能的變化和相應(yīng)的後果 ? List all Causes for each Failure Mode 列出失效模式的所有原因 ? List the current Controls for each cause 列出每個(gè)原因的現(xiàn)有控制手段 ? Assign Severity, Occurrence, and Detection ratings to each cause 給每個(gè)原因的嚴(yán)重度 ,頻度 ,可探測(cè)度評(píng)分 ? Calculate the RPN for each potential Failure Mode scenario 計(jì)算每個(gè)潛在失效模式的風(fēng)險(xiǎn)序數(shù) ? Determine remended actions to reduce High RPNs 提出降低風(fēng)險(xiǎn)序數(shù)的措施 ? Take appropriate actions 採(cǎi)取適當(dāng)?shù)拇胧? ? Recalculate RPNs 重新計(jì)算風(fēng)險(xiǎn)序數(shù) 52 FMEA ? Use the Process Flow Diagram format 適用流程圖的格式 – Identifies fabricate, move, store and inspect operations 識(shí)別四種作業(yè)類型 ,製造 ,移動(dòng) ,儲(chǔ)存 ,檢驗(yàn) – Identifies Key Characteristics 識(shí)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 /說明功能為 ： Verb + Object + Qualifier 動(dòng)詞 +賓語(yǔ) +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 53 FMEA ? A customer want or desire 顧客的希望或要求 ? Could seriously affect customer perception 有可能嚴(yán)重影響顧客的看法 ? Could lead to a customer plaint 有可能導(dǎo)致顧客投訴 ? 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(dá)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 the product 失效模式體現(xiàn)在産品上 54 FMEA ? Typical Failure Modes /幾種典型失效模式 ? Diameter out of spec. /直徑超差 ? Missing seal /漏裝密封墊 ? Cut strands /切破線皮 ? Missoriented part /部件方向錯(cuò) ? Insufficient solder /焊劑不足 ? Too much solder /焊劑過量 ? NFO, Flash /未充滿 ,飛邊 ? The ramifications of failure/後果是失效模式的衍生事件 ? The effect can be on /可能影響 ? The ultimate customer /最終用戶 ? Or intermediate customer (OEM, etc.) /中間用戶 ? A government regulation /政府法規(guī) ? The next process step /下工序 55 FMEA ? Customer plaints are a useful source of information 顧客抱怨是非常有用的資訊來源 ? An effect can be /後果可能是 ? Complete loss of function /功能完全喪失 ? Degradation of performance or quality /質(zhì)量或性能下降 ? Damage of process equipment /設(shè)備受損 ? Injury to an operator /員工受傷 ? Shutdown of an assembly line /停線 ? Effects of failure often show up as a chain of events, from immediate effect to the ultimate effect on the customer /失效的後果 通常表現(xiàn)爲(wèi)從對(duì)顧客的直接影響到最終影響等一系列連鎖反應(yīng) ? It is remended that these chains be developed for each failure mode and recorded on the FMEA form /建議針對(duì)每一種失效模式找出這些連鎖反應(yīng)，並記錄在 FMEA表上 56 FMEA ? A cause of failure is how the failure can occur in the process 失效原因就是過程爲(wèi)何會(huì)失效 ? Should be written in terms of something in the process that can be corrected and controlled 應(yīng)表述爲(wèi) 可糾正或可控制 的因素 ? Consider human error, wearout of tools, ambient conditions, and interactions of factors 如人的過失，工裝磨損、環(huán)境條件以及因素間的相互作用 57 FMEA Effects on the process /對(duì)過程的影響 ? 910 May endanger machine or operator / 可能導(dǎo)致設(shè)備或人員受損 ? 68 Scrap /報(bào)廢 ? 45 Sort and rework /篩選和返工 ? 23 Rework online /在線返工 ? 1 No effect /無影響 Consider Also the Effects on the Customer 還要考慮對(duì)顧客的影響 58 FMEA ? Use historical data (as a baseline) /利用歷史資料 ? Take improvements into account 考慮改進(jìn) 910 Failure almost inevitable /失效幾乎不可避免 78 Similar processes that have often failed in the past 以前類似過程常常失效 46 Similar processes that have occasional failures 類似過程偶爾失效 13 Similar processes that have experienced isolated failures /類似過程僅有過個(gè)別失效 59 FMEA CauseandEffect Chain 因果鏈 Tool Is Worn 夾具磨損 Tool Not Replaced 夾具未更換 Lack of Maintenance Procedure/沒有保養(yǎng)程序 Clamp Cracks at Bend夾子在彎曲處裂紋 Bundle Falls Out 線束散開 Rattling Noise 卡