A genetic algorithm for minimizing makespan of block erection in shipbuilding

Purpose - The purpose of this paper is to propose an algorithm based on genetic algorithm (GA) to solve the block erection scheduling problem in shipbuilding. Design/methodology/approach - The block erection scheduling problem is defined as the identical parallel machine-scheduling problem with precedence constraints and machine eligibility (PCME) restrictions. A GA is proposed to find near optimal solution, and a few lower bounds and the percentage of the reduced makespan are defined to evaluate the performance of the proposed algorithm. Finally, the GA for block erection scheduling problem in a shipyard is illustrated by using the real data from a local shipyard. Findings - The proposed GA produces lesser values of makespan against the random heuristic algorithm for the collected real instances. Research limitations/implications - The proposed GA can solve other similar parallel machine-scheduling problems with PCME to minimize makespan. Practical implications - Based on the proposed GA, the developed scheduling system for block erection in a shipyard can reduce the makespan of block erection, and contribute to the productivity improvement. Originality/value - The allocation of block erection to the crane is modeled as a parallel machine-scheduling problem with PCME, and the GA is developed to solve this problem to minimize makespan.