We examine a three-machine flow shop scheduling problem in which two overlapping waiting time limits exist between the first and second machines and the first and third machines, respectively. The objective is to minimize the total completion time. We first present a mixed integer linear programming (MILP) to mathematically model the problem and obtain optimal solutions.
Due to the high computational complexity of the problem, large-sized problems cannot be solved by the MILP within a reasonable computation time. We therefore develop a heuristic scheduling method based on the genetic algorithm. Finally, the performance of the proposed algorithm is numerically tested.