A genetic algorithm for
minimizing makespan of block
erection in shipbuilding
Bao Jinsong, Hu Xiaofeng and Jin Ye
School of Mechanical Engineering, Shanghai Jiao Tong University,
Shanghai, People’s Republic of China
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
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
Keywords Production scheduling, Parallel machines, Shipbuilding industry, China
Paper type Research paper
In the recent years, Chinese shipbuilding industry boomed because of the cheap labor,
and in China, the shipyards are running at peak load capacity. This calls for the
highest level of productivity improvement research. Efﬁcient planning is vital in
achieving high productivity. The manual planning system, which has been used, has
had a limited effect in the shipyard because of the unrealistic and untimely work orders
it gives. This results in work delays, accumulation of work-in-processes, etc. The
manual planning system also cannot respond quickly to the changing environment
since it takes a long time to ﬁnd a schedule manually. To tackle this challenge, many
shipbuilding companies are developing their own computerized planning systems.
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This work is funded by National 863 Program (No. 2007AA04Z100) and National Natural
Science Foundation of China (No. 050575137). And the authors acknowledge the assistance
provided by Hudong-Zhonghua Shipbuilding Co. Ltd.
Received November 2007
Revised July 2008
Accepted October 2008
Journal of Manufacturing Technology
Vol. 20 No. 4, 2009
q Emerald Group Publishing Limited