Research On Optimal Replenishment Policy For Products With A Random Defective Rate

Due to the influence of kinds of processes, such as the imperfect production system, the transportation and storage, products often contain partial defects. The defects cannot be used for sales. It takes some costs to deal the defects. Therefore, the inventory management for products containing defects becomes an important problem. The replenishment strategy for products containing de-fects is studied in this thesis, and the main content includes:(1) The problem of retailer’s replenishment cycle for products with a ran-dom defective rate is studied. The order cycle of products is assumed to be de-termined by the expected defective rate, order quantity and demand rate. At the end of the cycle, the residual will lead to depreciation, or the shortage will lead to the loss of sales opportunity. An inventory model optimizing the retailer’s expected profit per unit time is established. The calculation formulas of the op-timal order quantity and order cycle are given. Finally, the numerical examples are given and the effect of the main parameters on the optimal order quantity and expected profit is analyzed.(2) The inventory problem that multiple orders strategy is used and defects are consolidated is studied. Assuming that the defects are accumulated for mul-tiple cycles and shipped to supplier by retailer, an inventory model is established. The computational method of the optimal order quantity and order number is given. Sensitivity analysis of the main parameters is presented through the simulation experiments.(3) The replenishment cycle for products with a random defective rate un-der the trade credit is studied. The supplier and the retailer trade on credit. At the end of the cycle, the residual will lead to depreciation, or the shortage will lead to the loss of sales opportunity. An inventory model is established, and theoreti-cal results of the optimal solution for the model are given. Numerical examples are given, and the effect of main parameters on the optimal order quantity and expected profit is analyzed.