Considering The Flexibility and Overlapping in Operation in Job Shop Scheduling Based on Meta-heuristic Algorithms

Flexibility in job shop scheduling is a main problem that has been considered by many of researchers in recent years.So Scheduling for the flexible job shop is very important in the field of production management and combinatorial optimization. However, it is quite difficult to achieve an optimal solution to this problem in medium and actual size problems with traditional optimization approaches because of it’s high computational complexity. In this paper a new mathematical model based on considering overlapping in operation in the flexible job shop scheduling problem(FJSP) is developed and a hybrid metaheuristic algorithm called memetic algorithm (MA) is proposed to solve this problem.Also the objective function that we consider is minimizing the makespan time. The Numerical experiments are used to evaluate the performance and efficiency of the proposed algorithm. Results show that the proposed algorithm is capable to achieve the optimal solution for small size problems and near optimal solutions for medium and large size problems in a reasonable time.