Order assignment considering buyer, third-party logistics provider, and suppliers

This paper presents a fuzzy multiple-objective mixed-integer programming model that tackles some different features of order assignment problems by considering vague aspects of such decision-making problems, the model reflects realities encountered in practice. In particular, the model considers three main parties of the supply chain: the purchasing organisation, suppliers, and third-party logistics providers (3PL) and in doing so, considers the three main aspects of order assignment, namely purchasing, holding, and ordering. By applying the theory of fuzzy sets, and through some operations on objective function and constraints, this research achieves a mixed-integer programming model with less complexity and more performance in a group of order assignment problems.