A Brownian approximation of a production-inventory system with a manufacturer that subcontracts
成果类型：
Article
署名作者：
Bradley, JR
署名单位：
Cornell University
刊物名称：
OPERATIONS RESEARCH
ISSN/ISSBN：
0030-364X
DOI：
10.1287/opre.1040.0135
发表日期：
2004
页码：
765-784
关键词：
摘要：
This paper considers a production-inventory problem where a manufacturer fulfills stochastic, stationary demand for a single product from a finished-goods inventory. The inventory can be replenished by two production resources, in-house production and a subcontractor, which both have finite capacity. We construct a Brownian approximation of the optimal control problem, assuming that the manufacturer uses a dual base-stock policy to control replenishment from the two sources and that her objective is to minimize average cost. A closed-form expression is obtained for one optimal base-stock policy and an analytical expression is derived from which the other optimal base stock can be computed numerically. We show conditions under which the objective is convex in capacity, and the unique globally optimal capacity can be computed numerically. We thus provide a tractable approximation to the two-source problem, which is generally intractable. We demonstrate the accuracy of this approximation for an M/M/1 model. We also draw managerial insight from the Brownian optimal base-stock results into how the optimal base-stock policies control the inventory distribution and under what conditions the contingent source is used to build inventory or to resolve backorders.