Fault Tree Analysis is considered one of the more powerful analytical techniques applied within the aerospace industry to evaluate critical safety hazards. Fault trees provide a method of evaluating the systems operational risks of an undesirable outcome, where that undesirable outcome results from the system being in an unfavorable state and, while in that state, an unfavorable event occurs. This paper discusses the application of Fault Tree Analysis to evaluate system reliability and availability. It has provided an effective quantitative tool for evaluating the risks of simultaneous occurrence of two or more independent events which, in combination, are singularly undesirable. Experience in applying this technique to areas other than hazard analyses indicates that design and operational judgments are considerably strengthened, particularly on complex systems where the tradeoffs among several feasible alternatives may otherwise be highly subjective. The potential for general application of Fault Tree Analysis to commercial products appears attractive based not only on the successful extension from the aerospace safety technology to the nuclear reactor reliability and availability technology, but also because combinatorial hazards are common to commercial operations and therefore lend themselves readily to evaluation by Fault Tree Analysis. Therefore, it appears reasonable to conclude that the technique has application within the commercial industrial community where the occurrence of a specified consequence or final event would be of sufficient concern to management to justify such a rigorous analysis as an aid to decision making.