The FMEA can provide the following functions:
1. Systematic review of component failure modes to ensure that any failure produces minimal damage to the product.
2. Determining the effects that such failures will have on other items in the product and their functions.
3. Determining those parts whose failures would have critical effects on product operations, thus producing the greatest damage, and which failure modes will generate these damaging effects.
4. Calculating the probabilities of failure in assemblies, subassemblies, and products from the individual failure probabilities of their components and the arrangements in which they have been designed. Since components have more than one failure mode, the probability that one will fail at all is the total probability of all failure modes. One or more of these modes may be one that can generate an accident, whereas the others will not. Each mode must therefore be considered separately.
5. Establishing test program requirements to determine failure mode and rate data not available from other sources.
6. Establishing test program requirements to verify empirical reliability predictions.
7. Providing input data for trade-off studies to establish the effectiveness of changes in a proposed product or to determine the probable effect of modifications on an existing product.
8. Determining how probabilities of failure of components, assemblies, and the product can be reduced by using high reliability compenents, redundacies in design, or both.
9. Eliminating or minimizing the adverse effects that assembly failures could generate and indiating safeguardsto be incorporated if products cannot be made fail-safe or brought within acceptable failure limits.
In its original usages, failure modes and effects analysis determined where improvements in component life or design were necessary; and because failure intervals and probabilities wer estimated, maintenance periods and requirements could be established. FMEA has proven effective for both purposes. Deficiencies can be eliminated or minimized through design changes, redundancies, incorporation of fail-safe features, closer control of critical characteristics during manufacture and use, and extra care at the facilities of the subcontractors or users.
Effects of human actions on the product are not generally included in failure modes and effects analysis; these effects are considered to be the province of human engineering. Bioenvironmetal engineering is another area of investigation considered only from the standpoint of analyzing equipment required for environment control for failure modes and rates...
Hamar, Willie, Product Safety Management and Engineering, Second Edition, American Society of Safety Engineers, 1993, pages 151-153
