A method for achieving an enhanced mission capability

When reliability requirements are set for a system, the intended purpose is generally to maintain a performance capability in an operational environment. The current parameter of choice for stating reliability requirements is mean time between failure (MTBF). Mission reliability MTBF requirements are typically established to give a high probability that a performance capability will be maintained, with no failures, for a specified period of time. However, the actual operational profile for a system may be larger than the stated mission time. This extension to the nominal mission duration, however, is typical of many realistic use environments for complex system, both military and commercial. This often results in a low probability of success for many systems, if no provisions are made for repair. This paper discusses a methodology that addresses the success probability of this enhanced mission time with selected repair actions and spares.