Spatial scheduling for shape-changing mega-blocks in a shipbuilding company

Abstract

To overcome space restriction and to increase productivity, some shipbuilding companies use floating-docks on the sea instead of dry-docks on the land. In that case, a floating-crane that is capable of lifting very heavy objects (up to 3600 tons) is used to handle the blocks which are the basic units in shipbuilding processes, and therefore, very large blocks (also called mega-blocks) can be used to build a ship, but because there are some positional restrictions under which the megablock assembly yard can be constructed, the space is the scarcest resource in the process. The focus of the research reported in this paper is to develop an efficient spatial schedule for the mega-block assembly yard. First, we develop a lengthtime two-dimensional packing model for this problem. Since the optimisation model cannot be solved using an analytical method, we propose a GA-based heuristic algorithm using computational geometry theory. Through performing a series of computational experiments, we finally show that the proposed spatial scheduling algorithm can provide solutions of good quality very efficiently.

A Hybrid Heuristic Algorithm for Ship Block Construction Space Scheduling Problem

“…Compare and best , if < best , best = , best = ; else = + 1 and go to step (5). In this example, < best , so best = 24, best = {3, 5,2,4,15,14,7,6,9,8,10,11,16,17,12, 13}. After this improvement, the optimal solution reduces from 25 to 24.…”

“…Lee et al [10] proposed a ship block construction space scheduling problem and described this problem theoretically. Koh et al [11] solved the scheduling problem in shipbuilding company by heuristic algorithm.…”

Nesting and Berth Allocation by an Expert System Using Heuristic Search

“…Three-dimensional spatial scheduling, where a part is represented as a prism with service time as height, minimizing make span at block assembly shop is reported [6]. Reference [7] used genetic algorithm to solve a two-dimensional spatial scheduling problem for blocks with growing lengths as assembly progresses at pre-erection area in shipbuilding. Berth allocation problem is a two-dimensional spatial scheduling problem for seaside operations planning, in which a berth is allocated for each ship to load and unload freight within a specified service time [8].…”

A Branch and Bound Algorithm for Project Scheduling Problem with Spatial Resource Constraints

“…Next, the ship block erecting spatial resource scheduling problem was studied [26]. Furthermore, the ship megablock assembly spatial resource scheduling problem was tackled [27]. In other application fields, an operation system for reconfigurable embedded platforms was developed [28] and a bin packing problem with the constraint of precedence relationship was presented [29].…”