【正文】 ndication of a design weakness 設(shè)計(jì)薄弱部分的跡象 ? Consequence is failure mode 結(jié)果就是失效模式 ? List every conceivable cause/mechanism of failure 列出每個(gè)可以想到的失效起因 /機(jī)理 30 DFMEA 設(shè)計(jì)失效模式及后果分析 (15) Occurrence(O) ? The likelihood that a specific cause/mechanism of failure will occur ? Can only be reduced by a design change that removes or contros a cause/mechanism of failure ? Suggested Evaluation Criteria: Probability of Failure Possible Failure Rates Ranking Very high: Failure is almost inevitable ? 1 in 2 10 1 in 3 9 High: Repeated failures 1 in 8 8 1 in 20 7 Moderate: Occasional failures 1 in 80 6 1 in 400 5 1 in 2,000 4 Low: Relatively few failures 1 in 15,000 3 1 in 150,000 2 Remote: Failure is unlikely ? 1 in 1,500,000 1 Please refer to page 17 of the FMEA MANUAL 31 DFMEA 設(shè)計(jì)失效模式及后果分析 (15) 頻度 (O) ? 指某一特定失效起因或機(jī)理出現(xiàn)的可能性。 就象圖表所示 ,先排列出所有的風(fēng)險(xiǎn)順序值 ,然后優(yōu)先解決高分值問(wèn)題 50 PFMEA 過(guò)程失效模式及后果分析 (19) Remended Action(S) 建議的措施 – Intent is to reduce Severity, Occurrence, and/or Detection Rankings. 目的在于減小嚴(yán)重度 ,頻度 ,和 /或不易探測(cè)度的數(shù)值 – If effect could be a hazard to manufacturing personnel, cause must be eliminated or controlled or operator protection specified. 如果后果會(huì)危害制造人員 ,必須消除或控制其起因 ,或是明確如何保護(hù) – To reduce Occurrence ranking, process and/or design revisions are required. 為了減小失效發(fā)生的可能性 ,有時(shí)要修改過(guò)程和 /或設(shè)計(jì) – Only a design revision can cause reduction in Severity ranking 只有設(shè)計(jì)的修改 ,才能降低嚴(yán)重度數(shù) – Remember: if action is not taken to improve, the effectiveness of the FMEA is limited! 請(qǐng)記住 :若沒(méi)有正確有效的糾正措施 ,FMEA的效果會(huì)是很有限的 ! 51 PFMEA 過(guò)程失效模式及后果分析 (20) Responsibility/Target Date 責(zé)任 (對(duì)建議措施 ) /目標(biāo)日期 (21) Actions Taken 采取的措施 (22) Resulting RPN 糾正后的風(fēng)險(xiǎn)順序數(shù) 52 謝謝觀看 /歡迎下載 BY FAITH I MEAN A VISION OF GOOD ONE CHERISHES AND THE ENTHUSIASM THAT PUSHES ONE TO SEEK ITS FULFILLMENT REGARDLESS OF OBSTACLES. BY FAITH I BY FAITH 。 ? 推薦的評(píng)價(jià)準(zhǔn)則： (請(qǐng)參考 FMEA手冊(cè)的第 17頁(yè) ) Probability of Failure Possible Failure Rates Ranking Very high: Failure is almost inevitable ? 1 in 2 10 1 in 3 9 High: Repeated failures 1 in 8 8 1 in 20 7 Moderate: Occasional failures 1 in 80 6 1 in 400 5 1 in 2,000 4 Low: Relatively few failures 1 in 15,000 3 1 in 150,000 2 Remote: Failure is unlikely ? 1 in 1,500,000 1 32 DFMEA 設(shè)計(jì)失效模式及后果分析 (16)Current Design Control 現(xiàn)行設(shè)計(jì)控制 ? Validation/Verification activities which will assure adequacy of design 設(shè)計(jì)確認(rèn) /驗(yàn)證將保證該設(shè)計(jì)的結(jié)果是恰當(dāng)?shù)? ? Initial occurrence and detection rankings are based on these current controls 最初的頻度或不易探測(cè)度數(shù)取決于現(xiàn)行的控制方法 ? “ Current” is based on same or similar designs “ 現(xiàn)行”取決于