A new system-reliability assessment methodology

A methodology has been developed for assessing the reliability of electronic systems. This methodology consists of modifying a base reliability estimate with process grading factors for the following failure causes: parts; design; manufacturing; system management; induced; and no defect found. These process grades correspond to the degree to which actions have been taken to mitigate the occurrence of system failure due to these failure categories. Once the base estimate is modified with the process grades, the reliability is further modified by empirical data taken throughout system development and testing. This modification is accomplished using Bayesian techniques which apply the appropriate weights for the different data elements. Advantages of this new methodology are that it: uses all available information to form the best estimate of field reliability; is tailorable; has quantifiable confidence bounds; and has sensitivity to the predominant system reliability drivers.