关键词: 经济订货批量, 缺陷率, 模糊理论, 符号距离

Abstract: To deal with the imprecision problem of product defective rate and various uncertainties problems of ordering costs which were inherent in actual inventory systems,Economic Order Quantity (EOQ) problem with fuzzy defective rate and fuzzy ordering cost was studied. Firstly,the uncertainty existing in inventory management was described by using fuzzy theory,and then the fuzzy EOQ model with imperfect quality and fuzzy ordering cost was proposed. Thus the objective of the model was to determine the optimal order lot size to maximize the total profit. Then assuming that the defective rate and ordering cost were the triangular fuzzy numbers,the signed distance,a ranking method for fuzzy numbers,was used to de-fuzz the objective. After that an optimal lot sizing were proved,which could be reduced to the optimal lot sizing without uncertainties. And the corresponding profit per unit time was derived at the same time. Finally,a numerical example was provided to illustrate the results of proposed model. And by it,the influence of fuzziness of defective rate and ordering cost on the optimal lot sizing was also analyzed.

Key words: economic order quantity, defective rate, fuzzy theory, signed distance