How to Maintain the FMEA

      FMEAs are initially established in the early stage of product/process design and development. They're living documents and should be regularly reviewed and updated. Normally, FMEA review and updating should be triggered by the following events:

1. There're changes in the product/process requirements
      If there are changes in the product or process requirements, the FMEA team should review the changes and decide whether these changes can result in any new failure mode. If yes, document these new failure modes and complete the rest of FMEA accordingly.

2. A new failure mode is detected
      When creating FMEA, the FMEA team should list up all the failure modes that can occur to the product/process. Due to the limit of the team's knowledge, however, this list in most cases is not a complete list. Later on, when a new failure mode is detected, e.g. during design verification and validation, during mass production or during customer application, it should be included in the FMEA.  

3. A new cause is identified for a failure mode
      When creating FMEA, the FMEA team should also list up all the possible causes to each failure mode identified. Again, due to the limit of the team's knowledge, this list is often not a complete list. If a new root cause is identified in the failure analysis later on, it should be included in the FMEA.  

4. There's updated information to evaluate the ranking of S, O and/or D
      When creating FMEA, the FMEA team can sometimes only do the risk assessment (i.e. ranking of S, O and D) based on the best guess, as objective data or evidences are not available yet. With further deployment of the design and development activities, mass production and customer feedback, more and more objective data and evidences can be collected for more accurate ranking of S, O and D. When such information is available, the FMEA should be reviewed to re-evaluate and, if needed, to update the SOD ranking. For example, it is a common practice in factories that failure rate and cause of occurrence of each type of defects is consolidated on a monthly basis. These data should be used for the ranking of O, e.g. if a certain cause can result into a monthly failure rate of 0.2% for a certain type of defect, it indicates O=6 for this specific cause (according to the scoring criteria of AIAG's FMEA manual). If O is scored otherwise in the current revision of FMEA, it should be updated to reflect the actual situation. 
      If recommended actions are proposed, the FMEA should be updated later on to document the results of the actions. This should also be done after the actions are completed and objective data are available to evaluate the results.

5. The preventive and/or detective actions are found not effective
      As mentioned above, the risk assessment in the current revision of FMEA may not be accurate due to the limit of objective data. When these data are available, one may find out that SOD are severely under-ranked and the preventive and detective actions implemented are actually not effective. In such cases, more effective actions are should be recommended and the FMEA should be updated accordingly.

6. Proactive improvement is initiated
      One of the key principles in quality management is continual improvement. Following this principle, organizations should proactively initiate some improvement activities on a regular basis. FMEA is a good source to determine what kind of improvement activities can be initiated. It is a common practice that the FMEAs are regularly reviewed (e.g. annually), and top risks in the current revision of FMEAs are picked and actions are taken to further reduce the risks  (Please be noted that the current controls for the top risks are effective and the actions are not mandatory. Also please refer to this article on how to pick the top risks). These actions should be updated into the FMEA as the recommended actions, and the action results should be documented in the FMEA as well. 
.