Multi-objective model for multi-period, multi-products, supplier order allocation under linear discount

In this paper, a multi-objective mixed integer nonlinear programming model is proposed to solve the supplier order allocation problem. We investigated a problem where a single buyer orders multiple products from multiple suppliers in multiple periods. The model takes into account the linear discount pricing scheme, the suppliers' capacity limits, the delivery rate and the quality of the items, the minimum order quantities, and the budgetary limitations. The buyer should decide on how to allocate orders optimally between selected suppliers to maximize the total value of purchase while minimizing the total cost of purchase simultaneously. Finally, two numerical examples in discount and non-discount environments are given to illustrate the application of the model. The results show that order values can be largely influenced by supplier linear discount.