Instantaneous Storage Availability Model: Considering Spare Parts Degradation before Replacement

Availability is essential index for strategic weapons in storage mission. Spare parts replacement is an effective way to improve system storage availability. Normally, the performance degradation of spare parts before replacement is hardly considered in traditional instantaneous availability model. We established a instantaneous availability model using backward equation of semi-Markov Process (SMP) when considering the degradation time of spare parts before replacement. Our analysis indicated that availability had been great effect on when the performance degradation of spare parts is considered. An example is shown to express that this model could help policymakers to choose more suitable supporting plan.