Supplier Selection and Order Allocation of Recycled Plastic Materials: A Case Study in a Plastic Manufacturing Company

Supplier selection problem is one of the essential business activities related to sustainable development. This research conducted in a plastic manufacturing company that uses recycled Polypropylene (PP) type of plastic raw materials to reduce production costs and maintain the sustainability of the environment. The company faced some problems in supplier selection, which must be performed considering several criteria such as price, delivery, capability, and flexibility. In this paper, a decision-making process is proposed to solve the sustainable supplier selection in a multi-item and multi-supplier environment. This research proposes a model that combines the Best Worst Method (BWM), Technique For Reference Orders By Similarity To Ideal Solution (TOPSIS), and Multi-Objective Linear Programming (MOLP) to solve problems in sustainable supplier selection and order allocation. The results of this research can help managers to select suppliers and determine the optimal order allocation.