Inventory control is among the most important topics in operations research because of large investments in inventory and their effect on the profitability of the firms. A systematic analysis of inventory problems began with the development of the classical EOQ formula of Ford W. Harris in 1913,...

A mixed optimization technique for optimal machine replacement is presented which allows much more flexibility than previous models. Optimal purchase, maintenance and sale of a given machine between any two given points in time is treated as a subproblem, which one may choose to solve via...

We establish the computational complexity of the problem of minimizing makespan in a flowshop, where each jobs requires a pallet the entire time, from the start of its first operation until the completion of the last operation. We prove that the problem is NP-hard in the strong sense for m =2...

Cooperative advertising is a key incentive offered by a manufacturer to influence retailers' promotional decisions. We study cooperative advertising in a dynamic retail duopoly where a manufacturer sells his product through two competing retailers. We model the problem as a Stackelberg...

We investigate firms' re-manufacturing strategies in the case of a Cournot duopoly. On one hand, re-manufactured products cannibalize sales of new products by the same firm and hurt its profits. On the other, re-manufacturing can be a profitable marketing strategy to target different customer...

The method of variational inequalities is a useful theoretical tool in stochastic control, but there are few problems in which this method leads to an explicit solution. We present such a problem drawn from portfolio management. An agent can distribute his wealth between two investments, one...

We address the problem of finding an optimal financing mix of retained earnings and external equity for maximizing the value of a firm subject to random returns. The problem is formulated as a singular stochastic control for a diffusion process, and the value function satisfies a free-boundary...

We study infinite-horizon stochastic inventory problems with general demand distributions and piecewise linear concave ordering costs. Such costs arise in the important cases of quantity discounts or multiple suppliers. We consider the case of concave cost involving two linear segments. This...

Two types of quantity discounts are treated in the literature, namely, 'all units' discounts and incremental quantity discounts. In the all units quantity discounts model. the discount applies to every unit purchased. As a result, the total purchase cost is a discontinuous function of the...

This paper considers an infinite horizon stochastic production planning problem with demand assumed to be a continuous-time Markov process. Problems with control (production) and state (inventory) constraints are treated. It is shown that a unique optimal feedback solution exists. This solution...