Fuzzy Environment, Including Credit Payments And Product Defects, Inventory Theory

The competition between the enterprises in the modern society is more and more fierce. Considering the fast changing of the market information as well as the quicker renewal speed of the products and uncertainty factors affecting the enterprise operation getting more and more, the inventory management in the fuzzy environment plays an important role to the enterprise's development. Meanwhile, as a result of larger scale enterprises, the production and trading activities require huge capital flow, so, the credit pays becomes the main form of transaction. And caused by the imperfect production systems, natural disasters, goods damaged in the term of delivery, the defects are inevitable and lead to the cost of maintenance. All these factors present great challenge to management and decision. The enterprises are in urgent need of theoretical guidance on how to deal with the uncertainty and credit paid defective products" inventory management. Therefore, studying the credit paid and defective products under the fuzzy environment is practical and significant.The thesis takes credit paid and defective products as the research object to achieve minimum operating costs, analyzing the strategies for the credit paid and defective products inventory in the fuzzy environment .the thesis main contains:First, in the study of the EOQ model which refers to the credit payment and defect rate and out-of-stock is not allowed under the fuzzy environment, the thesis removed the issue of credit payment with quality products assumptions and defect product concept is introduced to the of credit to payment and expressed interest rate in the credit payment as a LR fuzzy number; Then, from the EOQ model which refers to the credit payment and out-of-stock is not allowed under the determined environment to EOQ model which refers to the credit payment and defect rate and out-of-stock is not allowed under the fuzzy environment, a fuzzy EOQ model was established to achieve the minimum cost.Second, in the study of the EOQ model which refers to the credit payment and defect rate and out-of-stock is not allowed under the fuzzy environment, based on the research of the credit payment and defect rate, the fist part of the thesis took the allowing out-of-stock inventory control into account, meanwhile, the credit payment and defect rate was expressed to a LR fuzzy number. A fuzzy EOQ model which refers to the credit payment and defect rate and out-of-stock is allowed under the fuzzy environment was established to achieve the minimum cost.Third, in the study of the credit payment and defect rate and maintenance cost under the fuzzy environment, the thesis removed the assumption that defective products could be detected in the past research; the maintenance cost was introduced to the study of inventory control. And with the demand, inventory holding costs, defect costs, interest rate, and defect rate are fuzzy numbers, a fuzzy EOQ model was established to achieve the minimum cost.