| In1915, the classical EOQ model is the preliminary research about the inventory control theory. Since the1950s, due to the increasing competition in the market and the deepening of economic globalization, the development of this research became a theory.In recent decades, more and more researchers have found that the number of inventory products had a certain influence on the products demand.Therefore, more and more researchers in the recent20years had brought the influence into the inventory control model, and obtained some research achievement.This article studies the model for productivity and demand rate are dependent the inventory level, the main content are as following:Firstly, we study a model which the stock dependent demand rate, where productivity is considered as a constant. After that we establish an average cost model about the system in a cycle, then, we analyze this model, and get the optimal strategy. A numerical example is given in the end of this part.Secondly, we study a model which the stock dependent productivity and demand rate is considered as a constant, where the rate of deterioration is also considered. After that we establish an average cost model about the system in a cycle, then, we analyze this model, and get the optimal strategy. A numerical example is given in the end of this part.Thirdly, the essay discusses a model for productivity and demand rate are linear dependent stock level, and deterioration rate is a constant. In this model the shortages are allowed to occur and backlog, under this condition we provides piecewise functions of productivity and demand rate which are all connect with stock level, and by using the model we gives a overall profit function in order to get the optimal solution. A numerical example is also given in the end of this part. |
