A New Heuristic Algorithm for the Preemptive and Non-Preemptive Multi-Mode RCPSPs

In this paper, a novel modeling and solving method have been developed to address the so-called resource-constrained project scheduling problem (rcpsp) where project tasks have multiple modes, and also the preemption of activities is allowed. to solve this np-hard problem, a new general optimization via simulation (ovs) approach has been developed which is the main contribution of the current research. in this approach, the mathematical model of the main problem is relaxed and solved; the optimum solutions were then used in the corresponding simulation model to produce several random feasible solutions to the main problem. finally, the most promising solutions were selected as the initial population of a genetic algorithm (ga). to test the efficiency of the problem, several test problems were solved by the proposed approach; according to the results, the proposed concept has a good performance to solve such a complex combinatorial problem. also, the concept could be easily applied to other similar combinatorics.