Lost-sales problems with Stochastic lead times: Convexity results for base-stock policies

成果类型:
Article
署名作者:
Janakiraman, G; Roundy, RO
署名单位:
New York University; Cornell University
刊物名称:
OPERATIONS RESEARCH
ISSN/ISSBN:
0030-364X
DOI:
10.1287/opre.1040.0130
发表日期:
2004
页码:
795-803
关键词:
摘要:
We consider a single-location inventory system with periodic review and stochastic demand. It places replenishment orders to raise the inventory position-that is, inventory on hand plus inventory in transit-to exactly S at the beginning of every period. The lead time associated with each of these orders is random. However, the lead-time process is such that these orders do not cross. Demand that cannot be met with inventory available on hand is lost permanently. We state and prove some sample-path properties of lost sales, inventory on hand at the end of a period, and inventory position at the end of a period as functions of S. The main result is the convexity of the expected discounted sum of holding and lost-sales costs as a function of S. This result justifies the use of common search procedures or linear programming methods to determine optimal base-stock levels for inventory systems with lost sales and stochastic lead times. It should be noted that the class of base-stock policies is suboptimal for such systems, and we are primarily interested in them because of their widespread use.