An Integrated Scheduling Algorithm Considering Both Urgent Insertion And In Process Delivery

So far,most of the integrated scheduling algorithms only address the static job shop environment and do not take into account the impact of dynamic problems generated on the subsequent processes during the actual production process,nor do they consider the dynamic rescheduling problem for both urgent and in-process products.Therefore,this paper proposes to study the problem of integrated scheduling that takes into account the delivery time of both urgent products and in-process products.The case comparison shows that the algorithm minimizes the production cycle time of each product by reasonably allocating the scheduling sequence between conflicting processes while ensuring the delivery time of urgent products and products in process.For the dynamic problem of inserting urgent products into the production process of in-process products,so this paper proposes an integrated scheduling algorithm that takes into account the delivery time of urgent products and inprocess products.The algorithm first connects the urgent product and the inprocess product with virtual root nodes to form a new virtual reconstructed process tree;for processes with overlapping start times on the equipment,the scheduling order and start times of each process in the product are determined by singleproduct merit strategy and elasticity comprehensive evaluation strategy based on the product superiority,process elasticity superiority and fit superiority.Case comparison shows that the algorithm minimizes the production cycle time of each product by reasonably allocating the scheduling order among conflicting processes while ensuring the delivery time of urgent products and products in process.For the integrated rescheduling problem of multiple urgent product arrivals in the process of processing products,this paper proposes an integrated rescheduling algorithm for multiple urgent product arrivals based on key chains.In the process of mixed processing of multiple products,the key chain composed of key processes governs the operation of the whole multi-product production system,and the algorithm proposes the key chain dominant scheduling strategy to solve the problem of weight distribution among processes.The algorithm proposes a hybrid rescheduling strategy for the three stages of the hybrid rescheduling process.For the initial static scheduling,the earliest start time and short time principle are used to schedule the processes;for the mixed product processing stage,the processes with overlapping start times are optimally ranked according to the process weight dominance value to determine the maximum completion time of the urgent product;for the remaining in-process product processes,the remaining in-process product processes are determined according to the process time level dominance value.For the remaining in-process product processes,the scheduling order of the remaining in-process product part processes is determined according to the process time priority.The case validation shows that the efficiency of the critical chain is effectively improved without increasing the time complexity,and the delayed processing of the processes in the critical chain is avoided.In order to solve the problem of urgent products disturbing the completion time of the production process in the symmetric two workshops,this paper proposes an integrated rescheduling algorithm for the symmetric two workshops that considers the arrival of urgent products.The algorithm divides the process selection workshop problem into two stages.First,it adopts a dynamic process chain ordering strategy to reconcile conflicting process sets based on product dominance values to avoid multiple processes from occupying the same equipment at the same time,and then determines the pre-selection shop for the process based on the shop where the immediately preceding process is located;finally,it uses a pre-scheduling Gantt chart and a shop balancing strategy to adjust the final processing equipment shop for the process.The algorithm optimizes the maximum completion time and the number of process migrations on the shop within the delivery period of each product.The results of the case demonstrate the feasibility and effectiveness of the comprehensive rescheduling algorithm based on the perturbation of urgent products.