The hazard potential (HP) is an abstract notion which could turn out to be as fundamental to reliability and survival analysis as the failure rate. We show that upon inception, all items and individuals are endowed with a potential to survive. The potential gets depleted with age and the item fails when this potential gets consumed. The endowed potential of any unit is unkown, but is always described by an exponential distribution. Thus all items have an exponential distribution on a suitably chosen time scale. This also holds in the multivariate case, except that each item has a different time scale. We demonstrate how the notion of HP can be used to generate classes of failure model subject to random and time varying stresses described by suitable stochastic processes, like the Levy process and its special cases.
Nozer's web site http://www.seas.gwu.edu/~irra/