Research On Flexible Production Shop Scheduling Problem Considering Batch Partitioning

China's traditional manufacturing industry is in an important stage of production mode transformation.It is gradually transforming from mass production and flow production mode to flexible production mode with multi type and small batch,which puts forward higher requirements for enterprises to realize efficient and intelligent production,Therefore,scheduling with lot streaming problem(SLSP)appears.Combining with the existing literature,scheduling problem considering lot streaming(LS)is further studied.Considering the production environment of flexible job shop(FJS)and flexible flow shop(FFS),the integer programming models of the corresponding scheduling problems are established based on the equal batching and consistent batch strategies respectively,numerical examples are given to verify the effectiveness of the proposed method.The main results are started as follows:Aiming at the batch scheduling problem of FFS,an integrated optimization model of batch partitioning and scheduling for FFS is established with the objective of minimizing makespan,and solved by GA.Considering the characteristics of the problem,a threesegment coding scheme based on order ordering,number of sub-batches and size of subbatches is proposed.By using genetic operator and tournament selection method based on elite strategy,combined with restart mechanism and local search algorithm,it can make up the deficiency of GA in local search.Through 24 sets of numerical experiments,the effectiveness of the proposed method is verified,the effects of different segmentation strategies on scheduling results are analyzed,and the superiority of the consistent batch splitting strategy is proved.Aiming at the multi-objective FJS batch scheduling problem,the optimization model of FJS batch segmentation and scheduling integration is established with the goal of minimizing the makespan and the shortest transportation distance,and then solved by GA.According to the characteristics of this problem,a three-segment coding scheme based on batch segmentation,process sequencing and machine selection is proposed.Using genetic operator and tournament selection method based on elite strategy,combined with restart mechanism,to make up for the shortage of GA in local search.The effectiveness of the proposed method is verified by numerical experiments,and the effects of different segmentation strategies on scheduling results are analyzed.The superiority of the consistent batch splitting strategy is proved.The results show that it is necessary to consider batch segmentation in flexible workshop environment.Considering batch segmentation has shorter production cycle,more balanced machine load and less idle machines than not considering batch segmentation.The results have certain guiding significance for improving the job management level of flexible workshop.