Finite Horizon Economic Lot and Delivery Scheduling Problem: Flexible Flow Lines with Unrelated Parallel Machines and Sequence Dependent Setups

This paper considers the economic lot and delivery scheduling problem in a two-echelon supply chains, where a single supplier produces multiple components on a flexible flow line (FFL) and delivers them directly to an assembly facility (AF). The objective is to determine a cyclic schedule that minimizes the sum of transportation, setup and inventory holding costs per unit time without shortage. We have developed a new mixed zero-one nonlinear mathematical model for the problem. Due to the difficulty of obtaining the optimal solution, especially in the instances of medium and large-sized problems, two meta-heuristic algorithms (HGA and SA) are proposed and evaluated over randomly generated problems. Computational results indicate that the proposed HGA outperforms the SA algorithm with respect to both the solution quality and computation times especially in large-size problems.