FMEA/FMECA – Engineering Services and Analysis
The FMEA and FMECA analyze a design to evaluate the potential for failures. It considers what can fail and how it fails (failure modes) and determines the effect of the failure. The FMECA also includes considering criticality or how harmful the effects of a failure mode are on system operation.
FMEAs/FMECAs examine the failure modes and causes of potential failures and determine the product's response to the failure. Steps can then be taken to change the design to eliminate the failure, reduce its impact, or compensate for the failure when it does occur.
FMEAs/FMECAs can be performed using a variety of standards, including MIL-STD-1629A and SAE ARP5580. MIL-STD-1629A provides calculations for criticality and allows ranking of failure modes dependent on severity classification. SAE ARP5580 combines the capabilities of MIL-STD-1629A and several automotive standards. As a result, the most notable difference in this standard from MIL-STD-1629A is the support of fault equivalencies. Fault equivalencies provide focus on management of failure consequences rather than managing individual failure modes.
There are two primary methodologies used for FMEAs/FMECAs – piece-part and functional:
- Piece-part FMEAs/FMECAs can be used to analyze a product at any level, from the piece-part level up to the subassembly or assembly level. At the lowest level, a FMEAs/FMECA can be performed by looking at each component in the product to determine the ways in which it can fail and how these failures affect the product. Subassembly or assembly level analyses are more limited in nature and not nearly as complex as an individual component level analyses.
- Functional FMEAs/FMECAs focus on the intended functions or use of a product. This type of analysis focuses on the functions of components, subassemblies, and/or assemblies and analyzes what happens if the function of the component does not occur.
FMEAs/FMECAs typically provide a brief system description, usually to the block level, to communicate what characteristics are being considered. They also provide a list of assumptions and practices that were used in the analysis.