Behnam Barzegar - Department of Computer Engineering, Nowshahr Branch, Islamic Azad University, Nowshahr, Iran
Homayun Motameni - Department of Computer Engineering, Islamic Azad University, Sari Branch, Sari, Iran

Job Shop scheduling problem has significant importance in many researchingfields such as production management and programming and also combinedoptimizing. Job Shop scheduling problem includes two sub-problems: machineassignment and sequence operation performing. In this paper combination ofparticle swarm optimization algorithm (PSO) and gravitational search algorithm(GSA) have been presented for solving Job Shop Scheduling problem with criteria ofminimizing the maximal completion time of all the operations, which is denoted byMakespan. In this combined algorithm, first gravitational search algorithm findsbest mass with minimum spent time for a job and then particle swarm Optimizationalgorithm is performed for optimal processing all jobs. Experimental results showthat proposed algorithm for solving job shop scheduling problem, especially forsolving larger proble

Gravitational search algorithm, Particle Swarm Optimization algorithm, Flexiblejob shop scheduling