Double-exponential-probability-distribution-function and it's applications in some critical aerospace safety problems: Perspective and brief review

Abstract

Some critical microelectronics and photonics aerospace-safety and reliability-physics problems could be successfully addressed using a flexible and physically meaningful double-exponential-probability-distribution-function (DEPDF). It is the author's belief that a successful outcome of an undertaking of importance cannot be achieved and assured, nor even considerably improved, if the effort is not quantified, and if, because of numerous uncertain-and-inevitable intervening influences, such a quantification is not done on a probabilistic basis. This is particularly true in various “human-in-the-loop” missions and extraordinary situations, when the reliability of the equipment/instrumentation, both its hard- and software, and the performance of the involved human(s) contribute jointly to the outcome of a mission or an off-normal situation. The acceptable never-zero probability of failure cannot be high, of course, but should not be lower than necessary either. It has to be adequate for a particular system, mission and application. Products that “never fail” are most likely more expensive than they could and should be. The general concepts are illustrated by practical examples. It is concluded that while some kind of predictive modeling should always precede any type of accelerated testing, analytical (“mathematical”) modeling, employed in this write-up, should complement, whenever possible, computer simulations: these two major modeling tools are based on different assumptions, use different calculation techniques, and if the results are in agreement, then there is a good reason to believe that the obtained information is sufficiently accurate and, hence, trustworthy. Future work should be focused on the experimental verification of the suggested DEPDF model and on new areas of its possible applications in aerospace safety tasks and problems and beyond.