Hybridization of simulated annealing with quenching for job shop scheduling

Different techniques based on heuristics are used by researchers to locate an optimal solution for Job Shop Scheduling Problem (JSSP). In this research study simulated annealing (SA) is hybridized with quenching to solve JSSP taking makespan as an objective function. Initially, the SA is started with high temperature with cooling under a defined cooling schedule. In the quenching cycle, used for intensified search in a local hyper plane of fitness function, temperature is reduced and numbers of iterations at one temperature are increased. The setting is reverted to normal upon completion of quenching cycle. The effectiveness of the proposed approach is measured through testing of 20 bench mark problems taken from literature, which shows that SA hybridised with quenching produced better results in 04 problems and the same best results in remaining 16 problems than conventional SA.