The solution approaches for multicriteria flowshop scheduling problems

Multicriteria flowshop scheduling problems have been one of the most attractive subjects in recent years. Among the multicriteria flowshop scheduling problems, very limited number of studies were performed on the problems which include tardiness criterion. In this thesis, six problems which include tardiness criterion were tackled. The first three of these problems are those in which the setup time was included in process time. The first one was the minimization problem of sum of weighted total completion time (J]C) and total tardiness (^T), the second problem was the minimization problem of sum of weighted total tardiness and makespan (Cmax). The third one was the minimization problem of sum of weighted total completion time, total tardiness and makespan. In literature, multicriteria flowshop scheduling problems including setup time were not considered much. For this reason, the three problems described above were studied by not including the setup time in the process time. In order to obtain the optimum solutions of these problems, up to 20 jobs were solved by setting up two integer programming models. In addition, the solutions of the problems with up to 2500 jobs were obtained by using the modified NEH method, tabu search and random search methods.Key Words : Flowshop scheduling, multicriteria, integer programming, heuristic methods, sequence-independent setup time.