Allocating production capacity among multiple products

We consider the problem of allocating production capacity among multiple items, assuming that a fixed proportion of overall capacity can be dedicated exclusively to the production of each item. Given a capacity allocation, production of each item follows a base-stock policy, i.e., each demand triggers a replenishment order to restore safety stocks to target levels. We present procedures for choosing base-stock levels and capacity allocations that are asymptotically optimal. Our objective is to minimize holding and backorder costs, or to minimize holding costs subject to a service-level constraint. Asymptotic optimality refers to large backorder penalties or stringent service-level constraints. Numerical results indicate that our rules perform very well even far from the asymptotic regime. A further approximation step results in allocation rules based on heavy-traffic limits; these, too, perform well.