Research for Spare Parts

This paper considers the problem of optimizing the benefits to be realized from allocating resources in a stochastic flow process. The Naval resupply system is viewed as consisting of several processes, from the requisitioning, to the processing, to the transportation of spare parts. The time necessary for completion of any of the processes by any of the assumed homogeneous items is a random variable described by a distribution function whose parameters are functions of the budget at which each process is supported. Having delineated alternative budget levels and associated parameter improvements at each stage, the problem is to allocate a fixed budget so that the probability of completion for any item over the whole flow system before a given deadline is maximized. The solution to this problem is presented with specific reference to the Naval resupply system.

The application of a theoretical inventory model to the problems of management of aviation spare parts is described in this paper. The results of this analysis suggest that the use of such models can be of significant benefit to the Navy, and are relatively simple to implement. Recommended stockage and ordering policies for ten parts currently being provisioned for the F-14 are discussed. Sensitivity analyses suggest several areas in which future studies should be undertaken.

In this paper, the reliability of a complex system is investigated. Special cases of the system include the 'spare parts' or 'standby redundancy' problem and the 'repair' problem. Also included in the system is the opportunity for 'cannibalization'. A theorem is given indicating the proper use of this activity. The spare parts problem and the repair problem are analyzed separately. Methods of combining the two analyses are then given in order to obtain bounds and approximations to total system reliability.