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...

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 advances significantly the literature on the optimality of the base stock policy by generalizing the demand distribution and beginning with a completely general belief prior to be updated as demands are observed over time. As the value function depends on the belief, the functional...

Robust optimization is a methodology that can be applied to problems that are affected by uncertainty in the problem's parameters. The classical robust counterpart (RC) of the problem requires the solution to be feasible for all uncertain parameter values in a so-called uncertainty set, and...

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...

In this study, we are primarily motivated by the research problem of recognizing heterogeneous customer behavior towards waiting for order fulfillment under the 'threshold rationing policy' (also known as the 'critical level policy'), and aim to find its effect on system stock levels and...

We present a new unifying framework for investigating throughput-WIP (Work-in-Process) optimal control problems in queueing systems, based on reformulating them as linear programming (LP) problems with special structure: We show that if a throughput-WIP performance pair in a stochastic system...

This paper analyzes the tradeoff between (demand) substitution costs and (production) changeover costs in a discrete-time production-inventory setting using a two-product dynamic lot-sizing model with changeover, inventory carrying, and substitution costs. We first show that the problem is...