multi-objective optimization model

The sustainable supplier selection (SSS) problem is an integral part of project procurement management. In this paper, a new extended grey relational analysis (GRA) based on the complex proportional assessment (COPRAS) is applied for SSS problems for using the merits of these two methods simultaneously. Furthermore, a new multi-objective optimization model (MOOM) is developed to obtain the objective weights of criteria. Moreover, to illustrate the uncertainty of real SSS problems and derived uncertainty of experts’ judgments, grey numbers are employed. To reduce the reliance on the experts, a new MOOM is developed for criteria’ weights determination. Finally, the performance of the introduced method is demonstrated by solving a numerical example.

Project procurement is one of the essential parts of the project covering a large portion of project costs. Supplier selection is one of the significant issues in project procurement. The appropriate supplier must be selected before ordering the materials needed for the project. Hence, a new combination of COPRAS and GRA methods is presented for choosing the best project’s supplier under uncertain conditions in this paper. Moreover, the weight of criteria is specified utilizing the multi-objective optimization model (MOOM). Furthermore, in group decision-making, decision-makers' importance is different because of varying education, views,  and experience. Hence, determining the weights of decision-makers is inevitable. Nevertheless, decision-makers' importance is specified by a new version of a combination of COPRAS and GRA methods. To evaluate the proposed model's performance, a numerical example is solved, and the results are investigated.