Consider a two-level inventory system consisting of one supplier and one retailer. The retailer faces a Poisson demand with a known rate and applies base stock (one-for-one ordering) policy. That is, his inventory position is set to a pre-determined level, so the demand pattern is transferred exactly to the supplier. The supplier has an inventory system and a service unit with exponentially dis...

We study a class of two echelon, serial systems with identical ordering capacities or limits for both echelons. For the case where the lead time to the upstream echelon is one period, the optimality of state-dependent, modified echelon base-stock policies is proved using a decomposition approach. For the case where the upstream lead time is two periods, we introduce a new class of policies call...

This paper considers a two-echelon distribution system which consists of a single warehouse serving N (possibly non-identical) retailers that face discrete stochastic demand of the customers. The warehouse orders from an exogenous supplier with ample stock. Orders arrive at the warehouse after a fixed leadtime. The warehouse satisfies, if possible, the replenishment requests from the retailers....

We consider a periodic-review single-location single-product inventory system with lost sales and positive replenishment lead times. It is well known that the optimal policy does not possess a simple structure. Motivated by recent results showing that base-stock policies perform well in these systems, we study the problem of finding the best base-stock policy in such a system. In contrast to th...

This paper is motivated by inventory problems arising in supply chains characterized by continuous replenishment programs based on information exchanged (reviewed) only intermittently between a manufacturing system (supplier) and a customer (retailer). When the replenishment is once-per-period, rather than at any point of time, a well-known result is the optimality of the so-called myopic base-...

This paper considers a multistage serial inventory system with Markov-modulated demand. Random demand arises at Stage 1, Stage 1 orders from Stage 2, etc., and Stage N orders from an outside supplier with unlimited stock. The demand distribution in each period is determined by the current state of an exogenous Markov chain. Excess demand is backlogged. Linear holding costs are incurred at every...

This paper is motivated by the inventory planning issues faced by a manufacturer of a digital projector. The seller faces demand from two sources: new demand, and demand to replace failed items under warranty. We model this setting as a multi-period single product inventory problem where the new demand in different periods are independent and the demand for replacing failed items under warranty...

We consider an N -stage serial supply chain with random demand, and study the problem of minimizing average inventory-holding cost subject to a pre-specified fill-rate constraint. Since the form of the optimal policy is unknown, we focus on base-stock policies. We present a bottom-up recursive procedure for policy evaluation and develop bounds on the optimal basestock levels. Using these bounds...

I this paper, we study a firm that faces demand from two sources: demand for new items and demand to replace failed items under warranty. We model this setting as a multiperiod single-product inventory problem where the demands for new items in different periods are independent and the demands for replacing failed items depend on the number and ages of the items under warranty. We consider back...

We consider a stock point for expensive, low-usage items that is operated by multiple decision makers. Each faces a Poisson demand process, and the joint stock point is controlled by a continuous-review base stock policy with full backordering. We consider penalty costs for backorders and holding costs for stock on hand. For this model, we derive structural properties of the resulting cost func...