Quick and situ-aware spatiotemporal scheduling for shipbuilding manufacturing

Abstract

Spatiotemporal scheduling of the block assembly process in shipbuilding is to determine temporal information including a time period when each block is under assembly and spatial information including an assigned bay and the placement of the block within the assigned bay. Due to a large number of discrete variables to optimize, finding an optimal schedule in a reasonably short time is almost impossible. Instead, we divide the problem into two phases where the first phase determines the bay assignment and processing start date for each block and the second phase determines the coordinates and rotation of each block in its assigned bay. Our objective is to find a block assembly schedule that minimizes the number of blocks that fail to be processed on time and unfairness in workloads across bays and days. The proposed algorithm is tested on six datasets of block information provided by Korea Shipbuilding & Offshore Engineering Co., Ltd. (KSOE). Our algorithm speeds up the scheduling process and finds schedules of higher quality compared to the original schedules that are manually planned by KSOE.