Planning and scheduling maintenance resources in a complex system

The inspection and maintenance policy is determined by the crossing of it critical threshold by an aggregate performance measure. Rather than examining the first hitting time of the level, we base our decisions on the probability that the system will never return to the critical level. The inspection policy is state dependent and we use a "scheduling function" to determine the time to the next inspection given the system state. Inspection reveals the true state of the system and allows the determination of the appropriate action, do nothing or repair, and the time of the next inspection. The approach is illustrated using a multivariate system model whose aggregate measure of performance is a Bessel process.