Unintended consequences of performance specifications for the reliability of military weapon systems

The use of performance specifications became a key US Department of Defense (DoD) acquisition reform in the 1990s. Gone were the detailed military specifications for parts and materials selection, workmanship, derating, and fault tolerance. Maximum use was to be made of commercial specs. Reliability would be specified only in quantitative terms such as Mean‐Time‐To‐Failure (MTTF) and/or the reliability R(t). However, there are significant differences between commercial and military weapon systems whereby performance specifications might bring in significantly greater mission risk. Reliability data from 1996 to 2000 might be an indicator of negative unintended consequences of the cancellation of military specifications. The acquisition of successful military systems requires a mix of performance and prescriptive reliability requirements that depend on the application, technology maturity, and complexity.