Preemptively scheduling a set of independent jobs with release time on one processor is a historical problem. In this paper, the same problem has been considered in which objective is to minimize the mean flow time. To prepare a perfect branch-and-bound, some optimality conditions have been represented and they have been compared with the optimality conditions which have been proposed before. O...

preemptively scheduling a set of independent jobs with release time on one processor is a historical problem. in this paper, the same problem has been considered in which objective is to minimize the mean flow time. to prepare a perfect branch-and-bound, some optimality conditions have been represented and they have been compared with the optimality conditions which have been proposed before. o...

This paper presents a new mathematical model for a bi-objective job shop scheduling problem with sequencedependent setup times that minimizes the weighted mean completion time and the weighted mean tardiness time. For solving this multi-objective model, we develop a fuzzy multi-objective linear programming (FMOLP) model. In this problem, a proposed FMOLP method is applied with respect to the ov...