Simultaneous Lot-Sizing and Scheduling for Single-Stage Multi-product Production-Distribution System with Due Date Considerations to Minimize Total Logistics Cost

This paper considers a simultaneous lot-sizing and scheduling for single-stage multi-product production-distribution system where each job has a distinct due date (deadline) and an arbitrary volume (size). The jobs are first processed on a batching machine, and then delivered to a pre-specified customer by a capacitated transporter. Each batch to be processed occurs a setup cost (setup time) as well a delivery cost (delivery time). Each job should be delivered to the customer before its due date. It is assumed that the job which is delivered to customer before its due date will occur a customer inventory cost, i.e. earliness penalty. The objective is to find a joint schedule so as to minimize the total logistics cost while guaranteeing a certain customer service level. We first show that this problem is NP-hard through a reduction from the Bin-packing problem, and then proposed a hybrid GA-SA algorithm for solving this problem. To verify performance of this proposed heuristic algorithm, we compare it with lower bounds of the problems. Numerical experiments show that the proposed hybrid GA-SA approach performs well in terms of both solution quality and time efficiency.