Investigation and Optimization of Closed-loop Supply Chain for Treadmill Production

Abstract

In recent years, fitness equipment closed-loop supply chains have become the mainstream thanks to the economic and environmental considerations. Using these networks, which are formed by integrating forward and reverse flows have become a core competency for corporations and societies. On the other hand, many factors of a supply chain network are subject to uncertainty; therefore, in the designing phase of those networks, the significant influence of uncertain factors shall be considered. With this respect, this research proposes the network design of a treadmill closed-loop supply chain system under an uncertain environment including manufacturing and re-manufacturing centers, collection and inspection centers, disposal centers, and retailers. Four types of treadmills including manual, professional, desk and hybrid are the focus of this research. The uncertainty discussed is about the vagueness of input data including the demands, the return flow, as well as disposal rate; which are regarded as fuzzy triangular numbers. Since a few of the parameters in the mathematical model have been assumed uncertain and fuzzy, the model has been formulated with fuzzy programming. In the next step, the uncertain model converts into its equivalent auxiliary crisp model. In the end, it was coded and solved using an innovative method with the help of GAMS software. Finally, the treadmill production data is used to determine the implication and applicability of the proposed fuzzy programming model as well as appropriate methodology. The results of this research can provide direction to help managers to make a better technical and tactical decision.