A meta-heuristic approach for the ELDSP in flexible flow lines: the power-of-two policy

In this paper, the problem of lot sizing, scheduling and delivery of several items in a two-stage supply chain over a finite planning horizon is studied. Single supplier via a flexible flow line production system (FFL) produces several items and delivers them directly to an assembly facility. Based on basic period (BP) strategy, a new mixed zero-one nonlinear programming model has been developed with the objective of minimization average setup, inventory-holding and delivery costs per unit time in the supply chain without any stock-out. The problem is very complex and it cannot be solved to optimality especially in real-sized problems. So, an efficient hybrid genetic algorithm (HGA) has been proposed based on applying the most applied BP approach i.e., power-of-two policy. Based on a number of problem instances, the solution quality of the algorithm has been evaluated and also compared with the common cycle approach. Numerical experiments demonstrate the superiority of the solutions of proposed HGA and indicate that is a very promising solution method for the problem.