Inventory Control Models for Logistics Planning and Operational Readiness with Cost Constraints 670655
It is quite widely acknowledged that a large part of the cost in deploying a weapons system in the field is the cost of spares provisioning. Historically, spares have been provided in a number of ways, not always directly related to the frequency with which things fail and seldom related to minimization of the cost entailed in such procurement. In this paper the authors will review some of the practical solutions which are open to the engineer wishing to maximize the probability of not incurring a system spares shortage under cost constraints, or wishing to minimize cost, while operating under some system spares shortage probability constraint.
In the terminology of inventory control systems, there are two different kinds of models in general which one might contemplate using for the usual spares provisioning situations, based upon the needs of the system being deployed. These model categories are:
Static models under risk
Dynamic models under risk
The first part of this paper will consider applications for static models under risk. The second part of the paper will apply dynamic models under risk. In general it may be said that static models apply for purposes of sparing initially, or on a “one-shot” basis; and that dynamic models apply when one is contemplating sparing over long periods of weapons system operation.
One purpose of this paper shall be to illustrate to the practitioner when, and under what circumstances various models should be used.