Research of Tugboat operation scheduling problem based on hybrid evolutionary strategy

According to Tugboat operation, this paper describes a special parallel machines scheduling problem based on flexible operation route and special process constraint. The schedule model whose objective is to minimize the maximum completion time is created. A Hybrid algorithm based on ES is employed, in which a coding method in accordance with the tugboat number is designed, which shows the quality of satisfying the process constraints automatically, two point crossover operation is used, Multiple Bit with random selection mutation is used to maintenance of population diversity. A local search algorithm based on exchange operation is set up to avoid sticking at local optima, according to the individual code. Finally, the validity of this algorithm was verified by an illustration.