FMEA培訓(xùn)-Define the scope for the FMEA英文版

1、FMEA Steps1Define the scope for the FMEA2Identify team members, customer, and knowledge experts3Develop roles and responsibilities for team members4Study the product / process / service5Develop rating scales for Severity, Occurrence, and Detection6Brainstorm failure modes, known and potential7List t

2、he effects, causes, and current controls for each failure mode8Assign ratings for Severity, Occurrence, and Detection9Calculate RPN10Decide on a threshold RPN11Prioritize based on RPN and severity, or as required by the customer12Identify corrective actions13Implement and verify effectiveness of cor

3、rective action14Complete the documentation1Define the scope for the FMEADefine the boundaries within which the product, process, or service will be studied, identifying the operating assumptions, current conditions, and constraints if any. Example 1: Conduct a Process FMEA on PCB manufacturing line

4、1, starting withoperation 10 and ending with operation 250. The assumption is that design of parts is correct, and no shortagesThe line is setup as shown in process flow drawing # 809901Example 2:Conduct Design FMEA on the pressure relief valve (Part #JJJKKK)for potential failures under extreme oper

5、ating conditionsAssume no preventive maintenance will be conducted once installedDocument on the FMEA startup formFMEA; Step by StepScope of the FMEAPoints to consider:Who are the customers for the FMEA, and what are their requirements / expectationsExample: Conduct (Process) FMEA on the assembly li

6、ne for Product A, covering operations 110 through 230 When will this FMEA be considered complete under the given conditions (Remember, FMEAs are considered living documents, as such they need to be updated / revised as things change.)Example: FMEA will be considered complete when the team has implem

7、ented all corrective actions as agreed upon based on the RPN threshold This will form the basis for deciding the level at which you should conductthe FMEA, and the scope of work involved.SystemSub systemComponentProcessServiceLevel FocusFailure CauseEffectModeSystem CarOverheating Cooling syst. Stra

8、nded on failurethe roadSub System Cooling SystemInadequate Thermostat Car Overheatingcoolant flow stuck closedSub Assembly ThermostatStuck closed Bi Metal SpringInadequate brokencoolant flowComponentBi Metal SpringBroken FatigueThermostat stuck closedImportant: You must be able to see a cascading of

9、 failure modes, causes, and effects similar to aboveExample of a Product Safety, LubricationEngine, Braking, Exhaust Trans., Cooling Thermostat Diaphragm, Bi Metal SpringRadiatorPump V BeltThe Influence of LevelCompanyPlant 1Plant 2Plant 3Plant 4PCB LinePower SuppliesFHP MotorsOp 10Op 20. Op 250FMEA

10、 can be conducted at any of these levels; it all depends on your objectiveThe Influence of LevelLevel FocusFailure CauseEffectModeSystem Factory (Plant 2)Late deliveries Low FPY Lost to customer on Line 2businessSub System Line 2 (Power Supplies)Low FPY High ReworkLate deliveries at / after testingO

11、peration TestingHigh rework Testing resultsLow FPY Op 210 inconsistent Example of a ProcessOp 120Op A20Op A10Op 10Op 210Op 240Op 250Important: You must be able to see a cascading of failure modes, causes, and effects similar to aboveThe Influence of Level2Identify team members, customer, and knowled

12、ge expert/sGet the team together, identify the customer and involve them in the process. Some preliminary work must be done to understand the product / process / service, so the right team can be assembled. Example:Team members include John Patton, Kirit Chawla (Customer rep) Kim Heaston, and Betty

13、Chung (Team Lead) No one knows enough about the process at this time.Document on the FMEA startup formFMEA - Step by Step3Develop roles and responsibilities for team membersWho does what in the team. Clearly define the roles and responsibilitiesfor each of the team members. At this time, it is impor

14、tant to consider thestrengths of each individual and leverage the same. Example:Team Lead:Coordinate the activities of the team, and keep on trackAct as cheer leader, and interface with managementEnsure the decisions are made with consensusCustomer:Define requirementsParticipate in developing rating

15、 scales, especially for Severity Knowledge Expert:As consultant provide info on details of product / process or serviceFMEA - Step by Step4Study the Product / Process / ServiceThe objective of this step is to acquire as much knowledge as possible. It is highly recommended that all team members delve

16、 into this, sincethere is no other way to familiarize yourself with the product / process / service.Example 1:The team responsible for conducting Process FMEA on gas panels production line spends 2 weeks on the line building gas panels, and testing the same. Example 2:The FMEA team responsible for D

17、esign FMEA on a medical implantstudies the way the product is going to be handled in the operating room, and used by the surgeon.Example 3:Four out of five members of the FMEA team spend 3 days with the phone operators, and order processing group to get first hand understanding of all the steps invo

18、lved in booking hotel rooms.FMEA - Step by Step5Develop rating scales for Severity, Occurrence,and DetectionOnce you have gained enough knowledge about the product / process / serviceand about the way it may be used by the customer / end user, you are in a position to develop meaningful rating scale

19、s. Most rating scales are on a scale from 1 to 10, however some may use a 1 to 5scale. Which of the two, is less important than ensuring that the same scaleis used throughout the company. You may have to develop / adapt the scales to suit your needsFor examples, see next pageFMEA - Step by Step Caus

20、es Failure Modes* Effects Occurrence Detection SeverityHow frequent?Who has the most info?If eliminated, will failure be avoided?How easy to detect with current controls?Who has the most info?If prevented will effects be eliminated?How severe?Who has the most info?Quantifying Failure Modes, Effects

21、and Causes* Causes may be used in place of Failure Modes in some cases5Develop rating scales for Severity, Occurrence,and DetectionExample from Design FMEA: Severity Occurrence Detection Effect Cause Failure Mode or Cause1 Remote chance, =200 for each failure mode:FMEA - Step by Step11Prioritize bas

22、ed on RPN and severity, or as required by customerArrive at the order in which you will start addressing the failure modes and causes for corrective action. Although RPN and severity based prioritization seems the most logical, your decision to proceed must be made with customer input. This step is

23、easily accomplished by sorting the data, in descending order. You can do this within each failure mode to maintain data integrity.Documentation on work sheet is important to ensure the whole team is in sync. FMEA - Step by Step11Prioritize based on RPN and severity, or as required by customerExample

24、 of sorted worksheet by RPN within each failure modeFMEA - Step by Step12Identify corrective actionIn this step you identify the corrective actions needed to eliminate / controlthe causes, and reduce the risk level to or below the agreed upon threshold.There will be times when you cannot work on the

25、 root cause; in such casesthe best course of action will be via addition of controls / adequate warningdevices / mechanisms of impending failure. Re-evaluate the ratings for S, O, and D, followed by RPN calculation.Discussion with the customer is important again since the corrective actions willimpa

26、ct them. Knowledge experts may also provide valuable input as to what kinds of corrective action will be best suited for the given cause / failure mode. Finally, from all possible corrective actions, the team may choose one based on cost / benefit analysis, speed of implementation, and the new level

27、 of risk. FMEA - Step by Step12Identify corrective action Example - all causes with RPN =200 are addressed: FMEA - Step by Step12 Identify corrective action Questions:Why did the cause of worn tires have an action item, although the RPN was 160?Training in advanced driving techniques reduces the RPN

28、 from 350 to 200, should he team stop here?Why is it that the severity rating does not reduce although training in advanced driving techniques is provided?Do you think the teams work is done?13Implement and verify the effectiveness of corrective actionCorrective actions identified ought to be implem

29、ented like projects - with a definitestart and end. In many cases a project teams may be formed to carry outthe implementation. These project teams may have members from outsidethe FMEA team, however at least one member should be drawn from the FMEA team. A check on the effectiveness of the correcti

30、ve action is important, in the absence of which you will not have a closed loop feedback on what really transpired.This check should be conducted by the FMEA team after the corrective actions have been in place for sometime. This is so because the corrective action, like a change, may not last. It t

31、akes diligent effort to ensure the change will have permanence. If the corrective action is not effective enough, you may need to implement some more controls / take more actions. 13Implement and verify the effectiveness of corrective action Example of additional action taken to reduce risk from dri

32、ving habits:14Complete the documentation and save in archives / databases This last step is overlooked by many of the FMEA teams. While it is understandable that the next project needs to be worked on, it is also important not to lose the knowledge gained by the team. The best way to document is to

33、use archiving systems in the company if they exist, electronic storage is now accepted by most regulatory agencies now. Items that should be saved include:FMEA startup formFMEA worksheetsMeeting minutesProcess flowDesign specs, and voice of customerDetails of projects created and implemented as part

34、 of action items Portables Cosmetic Process FMEA ResultsArea:Portables Mod 8Date Completed:1/5/98Team Members:Babak ShahmehriBrenda TurnerDick HolcombScott WiseAction Criteria: Failure Causes with RPN Numbers of 40 or HigherFindings:Area Found:Failure Causes:RPN #Actions:Assigned To:Notes:1WipedownR

35、ejecting all units for any defects due to lack of training on cosmetic standards, thereby causing delayed orders and higher unit costs 60Easy to use, operator-friendly criteria (pictures/overlays), cost of cosmetic defect repair study, more defined and up-to-date specsQuality Engineering, Production2WipedownRejecting all units for any defects due to hard to follow cosmetic standards, thereby causing dela