A Constraint Programming-Based Decomposition Strategy for the Block Assembly Scheduling Problem in Shipbuilding

Abstract

[Abstract] This study presents a novel Constraint Programming-based decomposition strategy to optimise block assembly scheduling in shipbuilding, addressing the complex Flexible Job-Shop Scheduling Problem with Assemblies, Limited Buffer Capacity, Block Erection Strategy, and Due Dates (FJSP-A-LBC-BE-DD). The proposed approach integrates buffer constraints and block erection strategies into a comprehensive CP formulation while introducing an innovative decomposition method that optimises makespan and resource allocation. Through experimental validation, the results demonstrate the effectiveness of this strategy, revealing that buffer capacity constraints play a critical role in scheduling efficiency, whereas the block erection strategy has a limited influence on makespan optimisation. The developed monolithic CP model for resource usage optimisation, combined with the decomposition strategy for makespan minimisation, provides a scalable and practical solution for industrial-scale shipbuilding scheduling. By outperforming existing models that overlook buffer limitations, this methodology establishes a structured framework for enhancing production planning. Future directions involve real-world applications and integration with simulation models for real-time re-optimisation.