Optimal Repairman Allocation Models

Abstract : A system of n components under the care of one repairman is modeled. The components are subject to failure, whereupon they may be repaired one at a time. It is desired to repair failed components in such a manner that the ergodic probability that the system works is maximized. It is assumed that each component and the system as a whole can be either working or failed, with the relationship between the working of the system and the working of the components given by a coherent structure function. The time a component works, or the time to repair a component is an exponential random variable of known rate. All components are independent, and at most one component may be under repair at a given time. Although the general problem is in principle soluble by known methods, computational difficulties are enormous for moderate sized systems. In addition, such methods give no general insight into the structure of the optimal policy. Therefore, bounds and approximations for general systems are highly useful.