A genetic algorithm approach for P / ST si,b / Zigma wj fj problem

In this paper, a genetic algorithm is presented for an identical parallel-machine scheduling problem with family setup time that minimizes the total weighted flow time (p /st s i,b/ zigma wj fj ). no set- up is necessary between jobs belonging to the same family. a set-up must be scheduled when switching from the processing of family i jobs to those of another family j, i = j, the duration of this set-up being the sequence-independent set-up time sj for family j. this problem is shown to be np-hard in the strong sense and obtaining an optimal solution for the large-sized problems in reasonable computational time is extremely difficult. further, it is computationally evaluated the performance of the proposed genetic algorithm solutions obtained using a mixed integer programming (mip) with the lingo 8.0 software.