A Novel Task-Package Partitioning Method for Shipbuilding Considering Four-Dimensional Features of Intermediate Products

Shipbuilding task packages are commonly defined from professional experience, which can produce heterogeneous work content within packages, dense coordination interfaces across packages, and uneven labor-time allocation. This study formulates task-package partitioning as a multi-objective combinatorial optimization problem with multi-dimensional engineering features and labor-time constraints. Four features of ship intermediate products—construction stage, structural type, spatial area, and functional system—are used to construct a model that increases intra-package cohesion, reduces inter-package coupling, and improves workload balance. A collaborative method combines genetic-algorithm global search with budget-constrained branch-and-bound refinement of boundary tasks. In a case containing 68 construction tasks from an 11,000 DWT bulk carrier, GA-B&B achieved a mean composite evaluation of 0.8403 over five independent runs, improvements of 18.9%, 3.4%, and 3.0% over a manual-rule baseline, pure GA, and NSGA-II, respectively. Its hypervolume was 0.6% higher than that of NSGA-II, while the number of nondominated solutions was reduced by 97.1%. The method improved partition quality and reduced the number of candidate schemes requiring engineering review, although local refinement increased computational cost. It therefore provides quantitative support for task release, crew organization, and labor-time allocation.