FMEA can be described as a bottom-up analysis where potential failure modes of a product or system are
identified, and the effects of these failure modes on a higher level are determined. For each potential failure
mode, the probability of occurrence and the ability to detect it are also determined. FTA uses top-down logic
to determine what failures (and in what combinations) can cause an undesirable event to occur. Both are
well-known and very old reliability analysis tools