A pseudo particle swarm optimization for the RCPSP

In this paper, a pseudo particle swarm optimization (PSO) algorithm is presented to solve the Resource-Constrained Project Scheduling Problem (RCPSP). The proposed algorithm uses the path relinking procedure as a way for the particles in PSO to fly toward local and global best positions. In order to prevent the premature convergence, a mechanism for maintaining the swarm diversity is used. The pseudo PSO algorithm imposes a distance greater than a threshold between the particles in the swarm. The distance threshold is reduced as the iteration number is increased. Extensive computational experiments were executed on standard benchmark problem sets of PSPLIB. The computational results show that the algorithm outperforms all of the other PSO approaches (known by the authors) applied to RCPSP and for the instance set j30, is competitive with the state of the art meta-heuristics.