Multi-objective Job Shop Scheduling Based On Multi-poplation-Variable Neighborhood Search Algorithm

The production scheduling of workshop is the foundation of the manufacturing system,and the optimization is the core of advanced manufacturing technology and modern management technology.Nowadays customers' demand is also becoming more and more novel,individuation and diversification.Multi-item and small batch production mode has been accepted by most enterprises.Such a mode causes complex production operation process which is not easy to control.A balanced production plan and operation plan are difficult to implement,therefore,it is easy to cause the problems on delivery quality and economic efficiency.Thus,the scheduling optimization problem emerge as the times require.In order to a better guide of the production,it is urgent to make much more study on the workshop scheduling problem in-depth and extensive.This paper studied the multi-objective flexible workshop scheduling problem in the actual production,and an effective and feasible optimization algorithm is obtained.The main contents are as follows:(1)Depth analysis of the characteristics of multi-objective job shop scheduling problem,and research status and multi-objective types.Summarize the basic multi-population genetic algorithm genetic manipulation method and its application status and trends in the field of shop scheduling optimization.(2)The advantages and disadvantages of multiple population genetic algorithm and variable neighborhood search algorithm are analyzed in detail.An improved multiple population genetic-variable neighborhood search algorithm is proposed.The algorithm uses a double encoding based on process and machine,and the introduction of external memory,elite reserved strategy are used.Furthermore,the communication strategies of population in vertical and horizontal is adopted.To ensure that the algorithm can efficiently solve discrete multi-objective combinatorial optimization problems.(3)The scheduling model base on MOJSP and aims at the minimum make span,the minimum machines load,and the minimum total load machine is established.The MPG-VNSA is applied in the model and the simulation experiment is conducted to verify the feasibility and effectiveness of the model and algorithm.(4)Shop scheduling program designed to optimize the core content production management information system,requirements analysis,overall design,database design,and detailed module design were conducted to develop the flexible shop scheduling simulation system.