The definitive source for FMEA is the AIAG (Automotive Industry Action Group), Look there first rather the many other sources you’ll find. I assume that your adviser’s reference to ontology is that an FMEA is properly used to identify how something might fail and how to reduce that possibility rather than to analyze how it actually failed. And, yes, an FMEA is properly done by a cross-functional team.
First you need to identify a specific process or product. If you are doing a proces FMEA you need to decompose the process into specific steps, For a product FMEA, identify the components of the product. Then identify the various ways (failure modes) that each step or component might fail. Agree on a numerical value for the probability. Descirbe the effect of each failure and assign a numerical value. Describe the current controls that can detect/intercept the failure and assign a numercal value. The RPN (Risk Priority Number) is the product of these three values. Starting with the highest RPN, find ways to reduce the risk of failure then recompute the RPN. You will need to demonstrate that the changes actually reduced the risk.
My primary tip is to use 1,3,5,7,9 for the numerical values. This makes it easier for the team to agree on a value and it helps to separate the RPN’s. Note that the order is reversed for detectability. 9 means highly probable, severe effect, but almost certain to be detected. 1 means highly unlikely, minimal effect, and unlikely to be detected.
Groll 9 years, 5 months ago.
