Reverse Integrated Scheduling Algorithm Considering the Workpieces’ Time Urgency Degree and Migration Cost

In the field of scheduling, complex products with a tree structure often exhibit inherent asymmetric characteristics, while their processing resources are usually provided by symmetric workshops with functionally equivalent and interchangeable processing equipment. Aiming at the complex product integrated scheduling problem with due date constraints, this paper proposes a reverse integrated scheduling algorithm considering the workpieces’ time urgency degree and migration cost. Firstly, internet-connected equipment with the same function as the main workshop and the lowest transportation cost is virtualized as symmetrical outsourcing workshop equipment. Secondly, the workpiece scheduling strategy and distributed integrated scheduling strategy are proposed. Taking each workpiece as the trial scheduling unit, under the premise of meeting the delivery time, the quasi-scheduling scheme with the minimum total migration cost for the current workpiece is selected as the workpiece scheduling scheme. If not unique, the scheme with the minimum outsourcing processing time is selected. Finally, the algorithm in this paper is compared with other algorithms in the same research field. The experimental results show that the algorithm in this paper reduces the total cost of workpiece migration by 25% and the total time of outsourcing processing by 20% while meeting the order delivery time. It is proven that the symmetric processing resource scheduling system constructed by the algorithm in this paper can achieve the parallel scheduling optimization of workpiece processing, assembly, and migration for both symmetric-structure and asymmetric-structure complex products.