Abstract:
In this paper, a continuoustime modeling method based on timeslots is applied to the scheduling of uniform parallel machines in order to obtain optimal solutions of this problem. Based on 3-index and 2-index assignment variables and different positions of empty timeslots on time axes, a series of continuoustime formulations are presented. To improve the efficiency further, a heuristic algorithm is proposed to reduce the number of timeslots. Finally, both the superiority and disadvantage of all the formulations presented in this paper are analyzed by some experiments. The experiment results show that 3-index models are faster than 2-index ones, and the arbitrary placing of the empty timeslots on time axes can speed up the solving process of models. Moreover, the proposed heuristic algorithm can improve the solving efficiency of models to some extent.