中文摘要：

供应商选择是复杂的多准则决策问题，需要同时决定供应商数量以及在所选供应商之间分配订购量，当考虑采购量折扣时，问题变得更为复杂．新方法在应用粗糙集理论对传统层次分析法（AHP）改进的基础上，建立了多目标混合整数规划模型，同时考虑了采购量折扣和供应商能力约束，实例计算证明该模型与求解方法是现实可行的．

英文摘要：

Supplier selection is a multi-criteria decision making problem in which two problems should be decided： which suppliers are the best and how much should be purchased from each selected supplier. When business volume discounts exist, this problem becomes more complicated. An integrated approach of analytical hierarchy process （AHP） improved by rough sets theory and multi-objective mixed integer programming was proposed to simultaneously determine the number of suppliers to employ and the order quantity allocated to these suppliers with supplier＇s capacity constraints in volume discount environments. A solution methodology to the multi-objective problem was presented and the results of a numerical example suggest that real-world applications of the proposed approach are both computationally practical and realistic.