A bicriteria flowshop scheduling problem with setup times

Most of research in production scheduling is concerned with the minimization of a single criterion. However, scheduling problems often involve more than one aspect and therefore require bicriteria analysis. In this study, bicriteria two-machine flowshop scheduling problem with setup times is considered. The objective function of the problem is minimization of the weighted sum of total completion time and total tardiness. An integer programming model is developed for the problem which belongs to NP-hard class. Only small size problems with up to 20 jobs can be solved by the proposed integer programming model. Heuristic methods are also used to solve large size problems. These heuristics are four tabu search based heuristics and random search method. According to computational results the tabu search based methods are effective in finding problem solutions with up to 1000 jobs.