This paper has shown that for electronic equipment decreasing failure rate with respect to time is the rule, and constant failure rate is the exception. Manufacturing flaws, failure mechanisms, and stresses that were studied for development of screening methods are believed to be identical to thos that cause failures in test and field operations. Therefore, the same failure theory, the Unified Field (Failure) Theory, is applicable from manufacturing, test and through field operations. Various mathematical models may be used with this theory.