Strategy

We address the combined problem of allocating a scarce resource among several locations, and planning deliveries using a fleet of vehicles. Demands are random, and holding and shortage costs must be considered in the decision along with transportation costs. We show how to extend some of the available methods for the deterministic vehicle routing problem to this case. Computational results using one such adaptation show that the algorithm is fast enough for practical work, and that substantial cost savings can be achieved with this approach.

Corporate investment in an economy without a complete set of contingent claims markets has the characteristic of a public good in the sense that the stockholders' consumption plans cannot be separated from, but depend on, the specific investment plans of the firms. The purpose of this article is to develop an internal allocation mechanism capable of attaining production plans that are unanimously preferred by stockholders and that satisfy a natural notion of optimality applicable to the stock market economy.

This paper establishes the existence of a solution to the optimality equations in undiscounted semi-Markov decision models with countable state space, under conditions generalizing the hitherto obtained results. In particular, we merely require the existence of a finite set of states in which every pair of states can reach each other via some stationary policy, instead of the traditional and restrictive assumption that ever stationary policy has a single irreducible set of states.

This paper presents methods for solving allocation problems that can be stated as convex knapsack problems with generalized upper bounds. Such bounds may express upper limits on the total amount allocated to each of several subsets of activities. In addition our model arises as a subproblem in more complex mathematical programs. We therefore emphasize efficient procedures to recover optimality when minor changes in the parameters occur from one problem instance to the next. These considerations lead us to propose novel data structures for such problems.

In continuous review models with a fixed delivery lag T, the state of the system is conveniently described by the net inventory position = (inventory on hand) plus (outstanding orders), in spite of most cost components depending on the actual inventory on hand. To relate these two inventory concepts one observes that the distribution of the inventory on hand at time t + T is determined by the inventory position at time t.

The recent appearance and growth of new delivery systems for dental services is examined from a marketing perspective. Analysis reveals that the growth of low priced, high throughput operations is consistent not only with marketing principles, but with the development of American retail institutions in general. Options for independent dentists in the face of this new competitive environment are discussed.