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...

This paper proposes a new methodology to solve partially observed inventory problems. Generally, these problems have infinite dimensional states that are conditional distribution of the inventory level. Our methodology involves linearizing the state transitions via unnormalized probabilities. It...

This paper proposes a new methodology to solve partially observed inventory problems. Generally, these problems have infinitedimensional states that are conditional distribution of the inventory level. Our methodology involves linearizing the state transitions via unnormalized probabilities. It...

We extend the linear programming (LP) model of deterministic supply-chain planning to take demand uncertainty and cash flows into account for the medium term. The resulting stochastic LP model is similar to that of Asset-Liability Management (ALM), for which the literature using stochastic...

In reverse logistics networks, products (e.g., bottles or containers) have to be transported from a depot to customer locations and, after use, from customer locations back to the depot. In order to operate economically beneficial, companies prefer a simultaneous delivery and pick-up service....

A production and inventory control problem is solved by a modified computational dynamic programming procedure. Specifically a two dimensional problem described by differential system equations with an integral objective function is solved by the proposed scheme. The numerical results are...

In this paper, the authors present an EOQ model with substitutions between products and a dynamic inventory replenishment policy. The key assumption is that many products in the market are substitutable at different levels, and that, in most cases, a customer who discovers that a desired product...

Care must be taken in extending the formulation and solution methodology of Federgruen and Zheng (1992) to include a stockout cost of a different dimensionality: $/unit, rather than $/unit/year. Federgruen and Zheng formulate this extended model for Poisson demand. We modify their formulation to...

This paper calls for a change in paradigm in lot sizing and scheduling. Traditionally, a discrete time scale is chosen to model lot sizing and scheduling. As an alternative, the so-called block planning concept is proposed which is based on a continuous representation of time. A mixed-integer...