Ingeniero

Computers & Industrial Engineering 56 (2009) 44–52

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Computers & Industrial Engineering
journal homepage: www.elsevier.com/locate/caie

A genetic algorithm to solve the storage space allocation problem
in a container terminal
Mohammad Bazzazi a, Nima Safaei b,*, Nikbakhsh Javadian a
a
b

Department of Industrial Engineering, MazandaranUniversity of Science and Technology, Babol, Iran
Department of Mechanical and Industrial Engineering, University of Toronto, 5 King’s College Road, Ont., Canada M5S 3G8

article

info

Article history:
Received 24 May 2007
Received in revised form 12 October 2007
Accepted 27 March 2008
Available online 4 April 2008
Keywords:
Storage space allocation problem
Container terminal
Geneticalgorithm

abstract
In this paper, an efficient genetic algorithm (GA) is presented to solve an extended storage space allocation problem (SSAP) in a container terminal. The SSAP is defined as the temporary allocation of the
inbound/outbound containers to the storage blocks at each time period with aim of balancing the workload between blocks in order to minimize the storage/retrieval times ofcontainers. An extended version
of a SSAP proposed in the literature is considered in this paper in which the type of container affects on
making the decision on the allocation of containers to the blocks. In real-world cases, there are different
types (as well as different sizes) of containers consisting of several different goods such as regular, empty
and refrigerated containers. The extendedSSAP is solved by an efficient GA for real-sized instances.
Because of existing the several equality constraints in the extended model, the implementation of the
GA in order to quick and facilitate achieve to the feasible solutions is one of the outstanding advantages
of this paper. The performance of the extended model and proposed GA is verified by a number of numerical examples.
Ó 2008Elsevier Ltd. All rights reserved.

1. Introduction
The temporary storage of the inbound and outbound containers
is one of the most important services at the container terminal that
is known as the storage space allocation problem (SSAP). The storage area in the terminal is divided into the several blocks of containers. Each block consists of a number of side by side lanes
with each lane includinga number of container stacks that are of
4–5 tiers of containers (Zhang, Liu, Wan, Murty, & Linn, 2003).
The fast storage and retrieval of containers at the blocks is
essential for the economic performance of container terminals
and also shipping companies. These issues affect directly on the
traffic of the handling equipment and consequently on the dwell
and turnaround time of vessels. Theprocess of the storing (or
retrieving) of a container includes the time for adjusting RTGCs,
picking up container, moving toward the allocation place and
downloading container. Since a container must be allocated to
(or picked up from) a certain place at the block, it may be necessary
to relocate one or more other containers for accessing to that container. This means a higher operating timeand cost for RTGCs.
Thus, it can be stated that balancing workload between blocks is
critical element of the efficiency of the container terminal and it

* Corresponding author.
E-mail address: safaei@mie.utoronto.ca (N. Safaei).
0360-8352/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved.
doi:10.1016/j.cie.2008.03.012

is important in reducing transportation costs and keepingshipping
schedules.
We extend the SSAP proposed in the literature (Zhang et al.,
2003) for a container terminal located at the south of Iran namely
Shahid Rajaei terminal. In this paper, the SSAP is extended in the
case that the type of containers is different such as regular, empty
and/or refrigerated containers. The difference between types of
containers is often resulted from the...