Researches On The Two-warehouse Inventory Problems With A Stock-dependent Demand Rate

The topic selection comes from the PhD. Programs Foundation of Ministry of Education of China (grant number: 20060359007): supply chain coordination with an inventory-level-dependent demand rate and National Natural Science Foundation Project (grant number: 70471045): supply chain coordination and quantity discounts research based on stochastic demand and asymmetric information.With the supply chain management carrying into extensively, more and more research developed on inventory control theory and the supply chain coordination. As the hot spot of logistics theory research, the theory and methods of inventory control are highly concerned by many enterprises; simultaneously, every member in the supply chain pursue maximization of their individual expected profits, which lead to double marginalization.Therefore, studying the problems of both inventory control and supply chain coordination has practical significance.During recent years, the research on inventory control models and supply chain coordination that has made much more progress is based on constant demand or price-sensitive demand or random demand. But few is based on stock-dependent demand. Furthermore, concerning of the economical effects, many enterprise's administrators adopt two-warehouse inventory system, in which one warehouse is own warehouse (OW) and the other is rented warehouse (RW) like "Central Warehousing Facility". In allusion to stock-dependent demand and two-warehouse system, the details are given as follows:1. The further research on the two-warehouse inventory models with a stock-dependent demand rate. (1)Under the assumption that the demand is linear with the amount of inventory, the two-warehouse inventory models are firstly extended with deteriorating items, and then a practical inventory model is offered for decision makers making inventory decision ,in which stock in RW is transported to OW in a intermittent pattern. Corresponding models are respectively built under two scenarios that shortages are backlogged or not backlogged. Lastly, sufficient scientific evidence is shown for inventory administrators deciding whether they need rented warehouse. (2)By employing deterministic quantity discounts, the dissertation has a further research on the two-warehouse system by assuming that the demand is the power function of inventory level. Models having analytic solution are offered for the retailer to make optimal order and transport policy correspondently. A prerequisite is given for the retailer to make inventory decision; and an algorithm of decision procedure is designed. Numerical examples are given to analyze the effect of the supplier providing deterministic quantity discounts for general items on the original order policy of the inventory system.2.This dissertation studies the coordinated problem of the two-echelon supply chain that consists of a manufacturer and a retailer. In allusion to a two-warehouse system with stock-dependent demand, we proposed mutual optimal lot size models and quantity discount pricing models from the points of cooperation and non-cooperation by considering the quantity discounts as decision variable, then we analyze the effect of the manufacturer providing quantity discounts on the original order policy and transport policy. Finally, we proved that quantity discounts as a coordinated policy can optimize the whole supply chain effectivelyThe research results presented above not only enrich the content of inventory control theory, but also widen the applied areas of supply chain coordination model, and provide more sufficient scientific evidence for decision makers making inventory decision.