A Multitime Window Parallel Scheduling System for Large-Scale Offshore Platform Project

Abstract

In order to complete the offshore platform project scheduling intelligently, an improved scheduling optimization system based on the parallel genetic algorithm was proposed. An optimal model for the large-scale offshore platform project scheduling problem (LSOPPSP) was built and produced the mathematic model of LSOPPSP, based on the characteristics of the abundance of activities, long duration, high uncertainty, and frequent changes. In long-term unsteady manufacturing, this model can provide good robustness. In addition, the essential steps of the multitime window parallel genetic algorithm were proposed. An improved population initialization algorithm was designed, as well as the coevolution strategy among populations was also proposed in parallel computing. These two strategies can increase population variety while also speeding up convergence. Finally, the suggested parallel scheduling system was deployed in our self-developed schedule optimization software for offshore platform enterprises, and the outperformance of the improved algorithm was proven by simulated examples and practical application.

Modeling of Digital Twin Workshop in Planning via a Graph Neural Network: The Case of an Ocean Engineering Manufacturing Intelligent Workshop

“…In the previous studies [44,45], focusing on the multi-objective optimization strategy of dynamic scheduling problems in the presence of uncertain events and proposing optimization algorithms for the makespan and optimal energy consumption, the ability to deal with event occurrences was theoretically developed. However, the prior algorithm research is based on definite assumptions, and the uncertain events appear randomly with probability, which is still partially deviated from the actual working conditions.…”

“…The benchmark analyzes the gap in the optimal solution, stability, and speed against GAT-DRL, with simultaneous PDRs [11] and Genetic Algorithms (GA) [45] solving the makespan of scheduling instances as well as the computation time. In particular, the PDRs are evaluated against four rules, namely, First-in-First-out (FIFO), Shortest Processing Time First (SPT), Longest Processing Time First (LPT), and Most Work Remaining (MWKR), which have the best overall performance.…”