Multiple Fault Diagnosis from FMEA

The Failure Mode and Effects Analysis (FMEA) design discipline involves the examination at design time of the consequences of potential component failures on the functionality of a system. It is clear that this type of information could also prove useful for diagnostic purposes. Unfortunately, this information cannot be fully utilised for diagnosis when FMEA has been performed by human engineers, because of inconsistencies in effect descriptions. The FMEA process is also very time consuming, with the consequence that the engineer can only deal with single point failures. Automation of the electrical FMEA process facilitates information reuse for diagnosis by providing consistent descriptions of failure effects, and by speeding up the FMEA process to such an extent that it becomes feasible to examine multiple failures. This paper introduces the advantages that automated FMEA provides for diagnosis, and describes its use for generating fault trees from the FMEA report. The paper examines the current limitations of FMEA use for diagnosis, and reports on how these limitations may be overcome. This paper appeared as pp1052-1057 in Proceedings of AAAI-97/IAAI-97, Providence, RI, July 1997.