An Integrated Robust Optimization Model for Supplier Selection and Order Allocation in a Supply Chain

In most industries the cost of raw materials and product components constitutes almost 60% percent of a product cost (in some industries up to 80%). In this condition، proper sourcing can play a key role in an organization's efficiency and effectiveness، because it has a direct effect on cost reduction، profitability and flexibility of a company. In this paper، to determine the optimal order quantity, multi supplier،
multi product and during several periods، shortage and surplus،
incremental discounts، multi objective and multi criteria nature of the problem، uncertainty in demand، lead time، fixed order cost، supplier quality level and every period budget are being considered. To incorporate the effective criteria in mathematical model، analytic network process approach has been used. After developing the robust multi objective mixed integer programming، a numerical example is presented. Finally, the results and suggestions for future studies are presented