Gregory A. DeCroix

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We analyze a multi-echelon inventory system with inventory stages arranged in series. In addition to traditional forward material flows, used products are returned to a recovery facility, where they can be stored, disposed, or remanufactured and shipped to one of the stages to re-enter the forward flow of material. This system combines the key elements of(More)
T here are many materials for which the quantity needed by a firm is at best indirectly related to the quantity of final product produced by that firm, such as solvents in manufacturing processes or office supplies. For any such " indirect " materials, an inescapable incentive conflict exists: The buyer wishes to minimize consumption of these indirect(More)
This paper analyzes a series inventory system with stationary costs and stochastic demand over an infinite horizon. A distinctive feature is that demand can be negative, representing returns from customers, as well as zero or positive. We observe that, as in a system with nonnegative demand, a stationary echelon base-stock policy is optimal here. However,(More)
This paper considers an inventory system with an assembly structure. In addition to uncertain customer demands, the system experiences uncertain returns from customers. Some of the components in the returned products can be recovered and reused, and these units are returned to inventory. Returns complicate the structure of the system, so that the standard(More)
In many supply chains consumption of indirect materials, sold by a supplier to a customer for use in her production process, can be reduced by efforts exerted by either party. Since traditional supply contracts provide no incentive for the supplier to exert such effort, shared-savings contracts have been proposed as a way to improve incentives in the(More)
We consider a system in which a single finished good is assembled from two components. Demand for the finished product is stochastic and stationary, and procurement and assembly leadtimes are constant. Unsatisfied demand is backordered. The inventory of each component or assembly is controlled by a separate firm using a base-stock policy. Each firm is(More)
We consider an Assemble-to-Order (ATO) system, in which inventory is kept only at the component level, and the finished products are assembled in response to customer demands. In addition to stochastic demand for finished products, the system experiences stochastic returns of subsets of components, which can then be used to satisfy subsequent demands. The(More)