Research On Flexible Process Sequence Shop Scheduling Methods Based On Whale Swarm Algorithm

A stable and efficient scheduling sequence plays a crucial role in improving the efficiency of a company.In most traditional shop scheduling problems,the processing sequence of different operations of one job are determined.However,according to the flexible process sequence there is no sequence restriction among the technics those have similar characteristics,so the processing sequence cannot be simply determined by a same rule.Besides,when companies generate a scheduling plan they usually consider more than one objective.Therefore,the flexible process sequence will cause different processing sequence,which will have an impact on the scheduling effect,so the research on Flexible Process Sequence shop scheduling problem(FPSSP)has very important research significance and value.In this paper,the method of FPSSP based on intelligent optimization algorithm is studied,and the single,the multi-objectives(makespan,total flow time,total machine idle time)FPSSP models are established by analyzing the characteristics of FPSSP.Then the intelligent optimization algorithms named Whale Swarm Algorithm(WSA)and Multi-objectives Whale Swarm Algorithm(MOWSA)based on the original WSA are designed to solve this problem.Firstly,the FPSSP mathematical model is established based on the characteristics of the Flexible Process Sequence shop scheduling problem,and then the framework and solution are put forward,which lay a theoretical foundation for the design of the solution method.Secondly,a WSA algorithm is designed to solve FPSSP mathematical model.Vector and matrix based encoding and decoding method is applied,and individual distance calculation strategy and individual moving strategy are improved,besides,three neighborhood structures are designed to improve the local search ability of the algorithm.Experimental results prove the WSA has better effectiveness than GA and ABC in solving FPSSP.Thirdly,a FPSSP with set-up time mathematical model is established,the decoding method with set-up times considered is applied and experiment results indicate that the WSA is better than GA and ABC.Then,a multi-objective with set-up time FPSSP mathematical model is established and the MOWSA algorithm is designed to solve it.The experimental results show that the designed algorithm is superior to NSGA-II in convergence and other comprehensive performance.Finally,the work of the whole paper is summarized and several future research directions are prospected.