Book Description

The reliability of certain airborne military electronic equipment in terms of measured mean time between failures (MTBF) has recently been shown to be between 3.5 and 6 hours. Reliability in this sense is usually based on actual measurement of time between failures rather than a statistical probability of failure occurring for a given period based on number of components. Improvement of reliability in this sense is based on a determination of the nature of the principal causes of failure and placement of them in the order of their descending probability of occurrence. Based on this ordering, one can often find ways of reducing the probability of occurrence of the causes of failure to the point where they can be considered to be random. Much of the control required for the high-probability causes of failure of electronics can be developed at the network design stage, since the electronic failure problem is frequently associated with either design difficulties or conditions of excessive heat in the environment. Particular emphasis is placed on data presentation herein, since experience has shown designers do work with inadequate information, a major part of the problem can be traced to inadequacies in characterization of components and devices, leading to excessive dissipation and excessive supply voltages. Further problems encountered as a consequence of the effect of a severe environment on a marginal design are discussed, and some ways of finding 'make-do' fixes are described. (Author).