Multi-echelon green supply chain model with random defectives, remanufacturing and rework under setup cost reduction and variable transportation cost

摘要

This article investigates a multi-echelon green supply chain system where a regular production process is integrated with a remanufacturing process in a single-setup-multi-delivery (SSMD) system under setup cost reduction. To reduce the setup cost, a discrete capital investment is introduced. A random number of the collected returned items are defectives which are uniformly distributed in the collected lot. The remanufacturing and manufacturing, both of the processes are imperfect. During the production run, they produce a random number of defectives that follow an exponential distribution. All these defectives are immediately reworked. Two models: Model-I and Model-II are developed in this regard. The transportation cost of the producer depends on the number of shipments which is a variable. The prime purpose of this study is to reduce the expected integrated total cost by optimizing the investment for setup cost reduction, common cycle length of all the buyers, total number of shipments, order lot size of each buyer, and delivery lot size of the producer. Numerical examples are provided to establish the models and the results show that Model-I can save more money than Model-II. Sensitivity analyses of the optimal solutions for both of the models are performed.