An effective asexual genetic algorithm for solving the job shop scheduling problem

The procedure solves the famous ft10 benchmark instance in 0.06s.The procedure strikes a balance between intensification and diversification.A Wide variety of constraints and performance measures can be handled.Based on the proposed algorithm, many innovative techniques can be devised.The algorithm can handle stochastic processing times. By using the notion of elite pool, this paper presents an effective asexual genetic algorithm for solving the job shop scheduling problem. Based on mutation operations, the algorithm selectively picks the solution with the highest quality from the pool and after its modification, it can replace the solution with the lowest quality with such a modified solution. The elite pool is initially filled with a number of non-delay schedules, and then, in each iteration, the best solution of the elite pool is removed and mutated in a biased fashion through running a limited tabu search procedure. A decision strategy which balances exploitation versus exploration determines (i) whether any intermediate solution along the run of tabu search should join the elite pool, and (ii) whether upon joining a new solution to the pool, the worst solution should leave the pool. The genetic algorithm procedure is repeated until either a time limit is reached or the elite pool becomes empty. The results of extensive computational experiments on the benchmark instances indicate that the success of the procedure significantly depends on the employed mechanism of updating the elite pool. In these experiments, the optimal value of the well-known 10i?10 instance, ft10, is obtained in 0.06s. Moreover, for larger problems, solutions with the precision of less than one percent from the best known solutions are achieved within several seconds.