EXTREME VALUE THEORY CONCEPT OR STOCHASTIC PROCESS APPROACH TO RELIABILITY IN FAILURE LIFE OR STRENGTH?

In the present article attempts have been made (1) to make clear the difference between the concept of extreme value theory and of stochastic process theory, and (2) to show that, nevertheless, distribution functions derived from stochastic process theory include for special cases exactly or approximately the same in appearance distribution functions derived from extreme value theory, and, furthermore, (3) to show which of these two theories is valid and useful in what types of failure. For time or cycle dependent failure, the stochastic process model may be sufficiently valid. On the other hand, for neither time nor cycle dependent brittle fracture, the extreme value theory model may be used as the case may be.