Job Shop scheduling with uncertain processing time based on ant colony system

Ant colony system is a novel emerged stochastic searching optimization algorithm in recent years. It provides a possible algorithm to solve complicated combinatorial optimization problems and interests many scholars. Ant colony system is applied to Job Shop scheduling with uncertain processing time, processing time of Job Shop problems is described with triangular fuzzy numbers, and the scheduling model with uncertainty is established. A method of ranking of fuzzy subsets and the improved ant colony system are used to minimize the make-span in Job Shop scheduling problem. The computational results show the efficiency of the proposed algorithm, and the influence of the algorithm parameter selection on the results as well as the range of uncertainty are discussed.