Failure Modes
About Failure Modes
After you have defined all the Functional Failures, you can define one or more Failure Modes for each failure. The analysis team should determine which Failure Modes are likely to occur. If the FMEA Analysis is being conducted on a system that does not yet exist physically, the mode(s) will be theoretical, unless other similar types of systems currently exist and historical data for those systems is available. Note that the SAE Standard JA1012, "Evaluation Criteria for Reliability-Centered Maintenance (RCM) Processes," recommends that an FMEA team review all modes in which deterioration, design defects, and human error could cause the failure.
Details
Failure Modes are often closely related to individual pieces of equipment or components of the defined piece of equipment. Values stored at the equipment level allow the team to link a mode to a location, the equipment to that location, and a component to that equipment. Maintenance and reliability statistics for failure modes can be stored at the equipment or component level, and can be analyzed and updated using the APM FMEA module.
The SAE Standard JA1012, "Evaluation Criteria for Reliability-Centered Maintenance (RCM) Processes," defines the following requirements for Failure Modes:
- All Failure Modes reasonably likely to cause each Functional Failure shall be identified.
- The method used to decide what constitutes a reasonably likely Failure Mode shall be acceptable to the owner or user of the asset.
- Lists of Failure Modes should include: Failure Modes that have happened before, Failure Modes that are currently being prevented by existing maintenance programs, and Failure Modes that have not yet happened, but that are thought to be reasonably likely (credible) in the operating context.
- Lists of Failure Modes should include any event or process that is likely to cause a Functional Failure, including deterioration, design defects, and human error, whether caused by operators or maintainers (unless human error is being actively addressed by analytical processes apart from FMEA).