An Integrated Scheduling Algorithm Based on a Process End Time-Driven and Long-Time Scheduling Strategy

The integrated scheduling problem is a classical combinatorial optimization problem. The existing integrated scheduling algorithms generally adopt the short-time scheduling strategy that does not fully consider the impact of the degree of process parallelism on scheduling results. In order to further optimize the total processing time of a product and the utilization rate of a device, an integrated scheduling algorithm based on a process end time-driven and the long-time scheduling strategy is proposed. The proposed integrated scheduling algorithm sets up a separate candidate process queue for each device and determines the scheduling order for each scheduling queue on the premise of satisfying the constraint conditions of the process tree. Driven by the process end time, the algorithm finds schedulable processes for each device. If the schedulable process is unique, it is scheduled. Otherwise, if the schedulable process is not unique, the process with long-path and long-time is scheduled. In particular, the scheduling strategies of the scheduling queues of different devices are symmetric, and the constraint relationships between the processes in different queues are asymmetric. The case analysis results show that the proposed integrated scheduling algorithm is better than some existing algorithms in terms of the total processing time of a product and the average utilization rate of devices. Therefore, the proposed algorithm provides a new idea for processing the scheduling of a single complex product.