Aiming at the existing two-workshop integrated scheduling algorithm with the same equipment resources, a unified vertical or horizontal scheduling rule is used to sort all processes and ignore the vertical and horizontal characteristics of the associated process position in the process tree, which affects the scheduling results. A two-workshop collaborative, integrated scheduling algorithm considering the prescheduling of the Root-Subtree processes is proposed. The algorithm proposes a process conflict adjustment strategy for the horizontal equipment constraints. The same equipment Root-Subtree processes are sorted and loaded into the corresponding equipment queue through the vertical and horizontal prescheduling method in a single-workshop environment, and it combines with the schedulable process set to dequeue the first process of the queue. To enhance the flexibility of process scheduling, it proposes a process conflict adjustment strategy for the vertical process tree constraints in the two workshops to determine the processing workshop of the processes and the actual start time, which narrows the search comparison for schedulable processes. The example tests show that the algorithm not only excavates and utilizes the effectiveness of the vertical and horizontal characteristics of the process tree, but also considers the process migration time. Therefore, the effect is better and more practical.

Given the existing integrated scheduling algorithms, all processes are ordered and scheduled overall, and these algorithms ignore the influence of the vertical and horizontal characteristics of the product process tree on the product scheduling effect. This paper presents an integrated scheduling algorithm for the same equipment process sequencing based on the Root-Subtree horizontal and vertical pre-scheduling to solve the above problem. Firstly, the tree decomposition method is used to extract the root node to split the process tree into several Root-Subtrees, and the Root-Subtree priority is set from large to small through the optimal completion time of vertical and horizontal pre-scheduling. All Root-Subtree processes on the same equipment are sorted into the stack according to the equipment process pre-start time, and the stack-top processes are combined with the schedulable process set to schedule and dispatch the stack. The start processing time of each process is determined according to the dynamic start processing time strategy of the equipment process, to complete the fusion operation of the Root-Subtree processes under the constraints of the vertical process tree and the horizontal equipment. Then, the root node is retrieved to form a substantial scheduling scheme, which realizes scheduling optimization by mining the vertical and horizontal characteristics of the process tree. Verification by examples shows that, compared with the traditional integrated scheduling algorithms that sort the scheduling processes as an overall, the integrated scheduling algorithm in this paper is better. The proposed algorithm enhances the process scheduling compactness, reduces the length of the idle time of the processing equipment, and optimizes the production scheduling target, which is of universal significance to solve the integrated scheduling problem. KEYWORDSHorizontal and vertical pre-scheduling; the priority of the Root-Subtree; the equipment process pre-start time; the dynamic start time strategy of the equipment process

Aiming at the existing flexible integrated scheduling algorithms that use unified rules to solve the conflicts between processes and equipment, and ignore the vertical and horizontal characteristics of the process relative positions in the process tree, a flexible integrated scheduling algorithm for dynamic determination processing equipment considering the Root-Subtree vertical and horizontal pre-scheduling (FISA-DEVH) is proposed. The process sorting strategy of the Root-Subtree vertical and horizontal prescheduling is proposed to sort the Root-Subtree processes of the same planned processing equipment in groups and load the Root-Subtree processes into the corresponding equipment queues, so as to fully explore the vertical and horizontal characteristics of the process. In order to give full play to the characteristics of the flexible equipment and realize the effective parallel processing between the processes, the flexible equipment optimal scheduling strategy of dynamically determining process is proposed to determine the final processing equipment of the process at each equipment driving moment and complete the production scheduling process from the Root-Subtree static pre-scheduling to dynamic fusion; The strategy uses the scheduling relationship between the unplanned processes and unplanned equipment to reduce the search scope of the combination scheme and improve the efficiency of the algorithm. The example tests show that FISA-DEVH has a better scheduling effect than the flexible integrated scheduling algorithm that processes the process tree with unified rules, and has universal significance for solving the flexible integrated scheduling problem.INDEX TERMS Flexible integrated scheduling, Root-Subtree vertical and horizontal pre-scheduling, the same planned processing equipment, the unplanned processes, the unplanned equipment