Inventory Models With Different Demand Characteristics And Partial Backlogging

Inventory management is a composition of business administration. It not only has a direct impact on the floating capital turnover of enterprise, but a critical impact on product sales. The service level should be improved as much as possible to reduce enterprise's inventory total cost, enhance its market competitive force.The basic theory of inventory management was illuminated, the task of inventory management, the component of inventory cost and relative theory of vendor managed inventory(VMI), were introduced; the literature search of partial backlogging, perishable items and VMI of independent demand item. Based on former research, one-stage inventory management and vendor managed inventory were investigated, under the condition of different demand characteristics and partial backlogging rates.Based on the classical EPQ model, an EPQ model for deterioration items with different lost sale factor relative to the inventory level during shortage period was developed. The existence of unique optimal solution is discussed by mathematic analysis and a numeric example. The sensitivity analysis shows that the parameter of losing sale has different impact on the costs of inventory system. The factors must be considered for the production inventory system to make management decision.A VMI model was developed with time-varying demand, sale price and purchase price, stock-dependent selling rate, and different service levels and the length of replenishment cycle under the condition that backlogging parameters are relative to the vendor's production stage. The sensitivity analysis shows that the demand increasing factor and the price varying factor have a greater impact on the total profit of supply chain than that of backlogging parameters. Enterprise should adjust the length and service level of every replenish cycle according to the demand, selling price and backlogging parameters.A VMI model with Partial Backlogging negatively related to customers'waiting time was established, where the vendor produce an integral number of the buyer's order quantity each time. It is showed by sensitivity analysis that the buyer should improve the service level and shorten the length of order cycle if the backlogging factor is big, and the buyer should lengthen the length of order cycle and reduce the times of order within the produce cycle if the vendor's productivity is big.