失效模式及其影響分析講座(英文版)(編輯修改稿)

　

【文章內(nèi)容簡介】 loss of subsystem function, * may require major rework may endanger machine /operator9 Very high * safetyrelated * production line shut down 10 * nonpliance with * saftety of prod personnel threatened government regulations~ Severity is the assessment of the seriousness of the effectHPhilips CFT Asia PacificInnovation Industrial SupportCZB698000006| 16 三月 2023 | 32Failure Mode and Effect Analysis ChartHPhilips CFT Asia PacificInnovation Industrial SupportCZB698000006| 16 三月 2023 | 33Potential Cause(s) of Failure* How the failure mode could occur, described in terms of something correctable or controllable* list, using brainstorming or Fault Tree Analysis (FTA), every conceivable failure cause assignable to each failure mode* causes should be specific, . “operator error” or “machine problem” are examples of causes which are not specific enough* causes may or may not be mutually exclusive if eradicating a cause has a direct impact on the failure mode, then,the cause is said to be exclusive to the failure mode when causes are not mutually exclusive, Design of Experiments may be use to identify the root causes (minor contributors) or thosewhich can be most easily controlledHPhilips CFT Asia PacificInnovation Industrial SupportCZB698000006| 16 三月 2023 | 34Fault Tree exampleProblemCause A Cause B Cause CA1 A2 B1 B2HPhilips CFT Asia PacificInnovation Industrial SupportCZB698000006| 16 三月 2023 | 35Occurrence (PFMEA)RatingDegree Based on SPC Base on failure rate1 Remote CpK 1 ppm2 Very low CpK 50 ppm3 Low CpK 250 ppm4 1000 ppm5 Moderate CpK 2500 ppm6 1 in 80 (%)7 High Not in Statistical 1 in 40 (%08 control 1 in 20 (%)9 Very high Failure almost 1 in 8 (%) 10 inevitable 1 in 2 (%)~ can be thought as the probability of occurrence of the failure modeHPhilips CFT Asia PacificInnovation Industrial SupportCZB698000006| 16 三月 2023 | 36Failure Mode and Effect Analysis ChartHPhilips CFT Asia PacificInnovation Industrial SupportCZB698000006| 16 三月 2023 | 37Current controls* Current controls are descriptions of controls that:(a) prevent the failure mode from occurringor (b) detects the failure mode should it occur* Examples of process controls: fixture foolproofing SPC inspection either at the subject operation testing or at the subsequent operations gauge R R preventive maintenance operator training GMP (good manufacturing practice) ISO 9000 SOP (standard operating procedures) humidity / pressure / temp controls finite element analysis calibrationHPhilips CFT Asia PacificInnovation Industrial SupportCZB698000006| 16 三月 2023 | 38Detection (PFMEA)Rating Degree Description1 Very High Process automatically detects failure2 Control will almost certainly detect failure3 High Control have good chance of detecting failure4 5 Moderate Control may detect failure6 7 Low Control have low chance of detecting failure8 9 Very Low Control probably will not detect failure10 Nil Control will not detect failure~ Assume the failure has occur, assess the probability that the controls will detect the failure mode before shipping outHPhilips CFT Asia PacificInnovation Industrial SupportCZB698000006| 16 三月 2023 | 39Failure Mode and Effect Analysis ChartHPhilips CFT Asia PacificInnovation Industrial SupportCZB698000006| 16 三月 2023 | 40Step 4 Define the Weak Points? Define the severity of the failure ( = S )Effect Rating : 1......... 10? Define the probability of occurrence of the failure ( = O )Cause Rating : 1 ........ 10? Define the likelihood of detection of the failure ( = D )Time Effect Rating : 1 ........ 10HPhilips CFT Asia PacificInnovation Industrial SupportCZB698000006| 16 三月 2023 | 41?Risk Priority Number : (RPN) = Severity x Occurrence x Detection= RPN = S x O x D 1 RPN 1000In themselves , absolute RPN numbers have no significance. They are only for ranking the failure causes, for corrective actionsHPhilips CFT Asia PacificInnovation Industrial SupportCZB698000006| 16 三月 2023 | 42RPN : Acceptance threshold? S = 5 (reduced performance + degradation)? O = 5 ( approximately %) ? D = 5 (may detect prior to shipment)Generally, RPN 125 may be a good threshold to useie for RPN 125 = corrective action is needed.But there are exceptions 。SxOxDRPN125S O D Description Action?10 1 1 Failure unlikely to reach user 1 10 1 Frequent Minor, detectable failure1 1 10 Minor defect reaches user infrequently10 10 1 Serious and frequent failure1 10 10 Frequent minor defect reaches user10 1 10 Serious defect reaches user10 10 10 IN TROUBLE!!!HPhilips CFT Asia PacificInnovation Industrial SupportCZB698000006| 16 三月 2023 | 43Step 5 Establish Actions and Responsibilities1. What has to be improved : change of design life test contact with supplier control point build in, in production process etc.2. Who is responsible3. When is it finishedHPhilips CFT Asia PacificInnovation Industrial SupportCZB698000006| 16 三月 2023 | 44RPNacceptable?Corrective actionsDONew RPN1Acceptable?EndYesNoNoYesRPNacceptable?Corrective actionsDONew RPNnAcceptable?EndYesNoNoYesHPhilips CFT Asia PacificInnovation Industrial SupportCZB698000006| 16 三月 2023 | 45Choice of Corrective ActionsUnlikely to be effective Preferred choices * Increase inspection * Pokayoke (foolproofing) * Additional test * Process change* Additional check * design change* Retrain operators * Automation* Rewrite SOP * Computerisation * Robot