An integrated process planning and scheduling system for block assembly in shipbuilding

This paper describes an integrated process planning and scheduling system for block assembly in shipbuilding. The system consists of process planning module, scheduling module, bottleneck block selection module, and process re-planning module. A rule-based reasoning technology is applied to determine optimal assembly units and assembly sequences in generating initial process plans. For scheduling module, a schedule revision heuristic is developed for efficient reallocation of blocks to alternative assembly shops. For bottleneck block selection which plays a central role in bridging process planning and scheduling, a powerful heuristic is developed by employing an entropy-based partitioning method for identifying bottleneck periods. The experimental results with data from a real shipyard show that our search heuristics are very effective and efficient.