On reliability growth testing

Reliability development growth testing (RDGT) is the most common method used to improve equipment reliability. The author had an opportunity to perform an analysis of hardware that experienced environmental stress screening (ESS), environmental qualification testing (EQT), RDGT and field usage. The failure mode and corrective action data were used to qualitatively assess the effectiveness of RDGT testing. The results of this analysis yield the following conclusions: (1) RDGT is not a very good precipitator of field related failure modes, therefore RDGT alone does not appear to be a strong driver of reliability growth; (2) RDGT, EQT, ESS, and EQT tests precipitate a high percentage of failure modes that occur only in “chamber-type” environments, and are not related to field use; (3) of the three “chamber-type” tests (ESS, RDGT, and EQT) evaluated as precipitators of field related failure modes, ESS appears to be the most effective; and (4) “chamber-type” tests are more efficient in developing corrective actions than field operation