Optimization of the Storage Sites for Export, Inbound and
Reorganize Containers by Timing Location
Mohammed Saleh
1a
, Attariuas Hicham
1b
, M. L. Ben Maâti
1c
and Hatem Taha
2d
1
Computer Science and System Engineering (CSSE), Abdelmalek Essaadi University, Av. Khenifra, Tetouan, Morocco
2
Research Operational and Statistic Applied(LAROSA), Abdelmalek Essaâdi University, Av. Khenifra, Tetouan, Morocco
Keywords: Container storage, container time, container terminal, artificial intelligence.
Abstract: Today, seaports subtend an increasing growth of containers stacking. Countries are striving to get the most
benefit from it and increase their share of this sector's resources, as well as optimizing their competitiveness.
Despite this increase, the ports suffer from many problems, including how to take the appropriate decision to
store and empty containers of various kinds. In this paper, we propose a method for storing containers at (El
Qasr El Saghir) terminal in Morocco, based on the hypothesis of time dynamics for choosing the optimal
location for the container in the yard. This hypothesis provides ideal storage locations for containers arranged
by time to avoid the accumulation of containers, reduce the forced movement of previously stored containers.
As well as facilitate the decision to relocate containers stored in the terminal to allow the provision of new
storage places, reducing time and operating cost. We propose to apply artificial intelligence (particularly
ANN) to this methodology (a case study on El Qasr El Saghir); for example, deciding for stacking containers
with different departure dates; because the parameters of our methodology are compatible with the ANN
algorithm.
1 INTRODUCTION
Without the ports, countries remain isolated from the
world. With it, communication horizons are opened,
the economy is strengthened and policies remain
independent, as it is one of the most important sectors
that support all industries, productive sectors, sustain
all sectors of the national economy which contributes
to promoting foreign trade and increasing
investments. Container terminals increase their
competitiveness and here it is clear that container
terminals face increasing pressure to maintain quality
of service to increase container productivity. The
increasing competition to improve efficiency at
container terminals has attracted the attention of
process analysts. According to (Stahlbock & Voß,
2007), (Murty et al., 2005) (Vis & de Koster, 2003),
overviews of operations and process problems at
container terminals and references on methods for
solving problems of these processes. In this paper, we
a
https://orcid.org/0000-0001-9394-1659
b
https://orcid.org/0000-0000-0000-0000
c
https://orcid.org/0000-0000-0000-0000
d
https://orcid.org/0000-0001-8025-5289
examine one of these important operational problems:
allocating storage locations for inbound containers,
export, and reshuffles.
According to (Salebeh, T. & Debo, A., 2020) the
storage yard of the container terminal is divided into
large storage areas called blocks. Figure 1 shows a
typical storage block in a station. Usually, these
containers are either outbound or inbound. Each type
has different characteristics (e.g., type, arrival
time/date, departure time/date, weight). Containers of
different sizes arrive through ships and are loaded
onto external trucks or trains called incoming
containers and on the other hand, export containers
are brought by trucks or other means of transport to
be loaded onto ships where the time of arrival of the
means of transport is unknown compared to the time
of arrival and departure of ships (Murty et al., 2005),
(Zhang et al., 2003).
The slot is the smallest storage unit in the location
for one container, where the container in this storage
Saleh, M., Hicham, A., Ben Maâti, M. and Taha, H.
Optimization of the Storage Sites for Export, Inbound, and Reorganize Containers by Timing Location.
DOI: 10.5220/0010733700003101
In Proceedings of the 2nd International Conference on Big Data, Modelling and Machine Learning (BML 2021), pages 333-338
ISBN: 978-989-758-559-3
Copyright
c
2022 by SCITEPRESS Science and Technology Publications, Lda. All rights reserved
333
position is naturally located with its longest side
either on the floor or precisely on another container
(of the same size). Containers are stacked one on top
of the other to form a column and the pillars are
placed together by the longest of them side by side to
form a bay.
The block is formed by placing many bays
together so that the container's doors are in one
direction at the front and the end in the other
direction. The locations of the same level in a block
form a tier. Columns that stack next to each other in
the block form a bay.
Joining two bays together in the block constitute
the Paired-Bay. In general, ternary (row, tire, bay)
specifies (r, t, b) coordinates of the (container)
location in the block. The length of the block is
determined based on the number of bays grouped by
the design of the storage yard and it is usually
approximately 20. The width (the number of rows)
and height (the number of tiers) of the block are
determined by the type of yard cranes used in the
block. The most common type of yard cranes, Rubber
Tire Gantry Cranes (RTGC), generally have a bridge
spanning six bays of containers stacked from four to
five levels high.
Figure 1: A container - Storage Paired-Bay in block
Railroad Structures Fixed Quay Cranes (RMGC),
which are larger than its predecessor, as it extends
over 13 rows of containers stacked at six heights and
there are other types of yard cranes, of different
widths and heights, for stacking (Salebeh, T. & Debo,
A., 2020).
Furthermore, we found in literary studies that
some container terminals adopt different storage
methods that meet their need. The large container
terminals have separate storage areas for export and
import containers and temporary areas designated for
containers that have just been emptied from or loaded
onto ships. Sometimes the export and import
containers are mixed into blocks, sometimes even in
bays. The adoption of these methods forces the station
to rearrange mixed containers based on species
distinction and the reorganization of future retrieval
operations. This increases the cost, time, effort of the
cranes; there is no doubt that this reduces the
productivity and competitiveness of the terminal.
This process (rearrangement) requires informed and
appropriate decision-making as it affects the
efficiency of the container yard's productivity (Kim
& Park, 2003). (Cobo, 2018) Present a general
dynamic pattern of container arrival and expected
handling effort for storage yard equipment by
proposing a methodology for allocating space for
outbound container storage and one place for each
outbound container.
According to (Voß et al., 2004), in the first part,
sites in the yard are reserved before the ship’s arrival
and then the containers are grouped, the weight
principle is adopted between the lighter and then
heavier containers to ensure the stability of the vessel.
In the second part, some terminals use online
procedures that do not require a pre-booking
reservation of space and that adopt scattered
planning. When a new container arrives, the berthing
location of the vessel is determined and then a good
location for the container is located in the specified
space in real-time, according to the category.
According to (Zhang et al., 2003) presented his
study on two levels; the first level worked to reduce
berthing by merging the work of the (Quayside
Crane) and storage yard cranes (RTGs) to scatter
containers between different blocks, whether
outgoing or incoming. The second level provides a
detailed solution to reduce the outbound container
transport distance between the block in the storage
space (block) and the ship's berthing place. In this
paper, we study in detail the problem of allocating
storage locations to determine the optimal location for
the container storage in the terminal yard.
According to known stowage schemes for ships
and container handling sequence, the problem of
optimized site allocation arises when import/export
containers arrive; these site allocation decisions are
made continuously in real-time as inbound/outbound
containers arrive and depart. This paper shows the
sequence of handling container storage according to
the characteristics referred to in the information of
arrival containers (Figure 3).
This method can deal with the problem of
container's locations in blocks, especially in bays,
because it enough to solve the problem of allocating
a site for the container in the block, allocating the site
in the bay and therefore the best slot in the bay is the
best slot for the entire block in the terminal. If the
activities in the storage yard are not properly
coordinated, ill-advised and costly rearrangements
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334
are carried out and cause traffic congestion from the
carriers. Indeed this one-stack problem is very
complex (Avriel et al., 2000). Hence it is only natural
that studying the detailed site allocation problems of
a single stack is ineffective in the block.
In this approach, we first present a two-part
methodology of bay-timing. The first is the allocation
of double bays in the block and the second part
addresses the problem of allocating ideal sites for
storing containers. In general; the methodology
divides the blocks into Paired-Bays, in which the
incoming, outgoing, and refrigerated containers are
stored with taking into account the characteristics of
each type. The methodology is mainly based on the
exact time for each container location, which gives
the Paired-Bay the time mechanism. Then we
determine the ideal location for the container by the
previous content of the bays with the inclusion of the
variables related to the bay and the containers (Figure.
3). The methodology and its flexibility are discussed
in the section (Methodology).
Sharing, analyzing, and utilizing operational data
in real-time is essential, so we need the best ways to
use it; applying artificial intelligence is a perfect
solution for processing the big data generated by this
method or similar methods. Dealing with the huge
amount of data resulting from this problem is a
challenge in itself, in addition to making appropriate
and well-informed decisions. Undoubtedly, applying
artificial intelligence techniques to analyze this data
will be a much more intuitive and effective method
than any traditional method can do. The rest of the
paper is structured as follows: Section 2 presents the
methodology and scenarios. Section 3 presents
Artificial Intelligence. Finally, Section 4 concludes
the study.
2 THE METHODOLOGY OF BAY-
TIMING
When a ship arrives, the person responsible for
managing the terminal has information about the
containers (number, type, time/date of the arrival,
time/date of the departure, etc); he will allocate places
for these containers in a way that does not affect the
departure of the previous containers. This issue raised
an important question: How does one know what is
the date and time of receiving a container and how
can we reduce the time, cost, and operational effort?
Looking for an answer to this question ensures that
the container is not buried in the depths of the piles
when it is time to leave the yard, which reduces the
number of operations required to reach the container
in question. We propose the methodology of "Bay-
Timing"; It is a methodology for managing locations
within a block, which operates the location inside
bays according to time, specifically chronic two bays
in one block. This study demands that the container's
location in the storage yard be arranged according to
the departure time as if each slot of the container is
defined by date-time and therefore the processing of
containers storage begins according to the containers
with the farthest time range.
First, we formulate the following definitions:
Paired-Bay: is the even division of bays in a single
block.
Chronic-Bay: is a suggested method for linking the
bay with a specific date-time based on the time range
of the containers that are stored in the bay so that
maintains the arrangement of storage and disbursing
and also rearranging the containers.
Figure 2: Attributes used in the methodology
Reserved Bay: is a Paired-Bay that is reserved in
each block with the aim of flexibility to re-store the
containers in exceptional cases that do not comply
with the methodological standards for storage, such
as the one that expired the period allowed in the bay
designated for storage in the terminal yard and the
storage in it is processed on an individual basis.
The Paired-Bay reservation methodology
provides the ease and flexibility of storing a batch of
containers with different dates (known or unknown);
this is what we will try to clarify through this section;
the Paired-Bay methodology divides a block
consisting of six rows, four layers, eight bays (four
Paired-Bays (8/2 = 4). So, one block capacity = 6 * 4
* 8 = 192 locations. Figure 3. shows only one row
with four tiers in the length of four Paired-Bay.
Optimization of the Storage Sites for Export, Inbound, and Reorganize Containers by Timing Location
335
Figure 3: Paired-Bay in the block
In general, for each location, whether vacant or
full, there is a row number, tire number, and bay
number, and this location is denoted by the symbol
(P). We present the following notation that used in the
Paired-Bay methodology (Figure 3.):
N: the total number of slots. n: the rank of slots.
X: the Input(the container).
s: slot, r: row, t: tier, b: bay, pb: Paired-Bay,
Pe: Position_empty (vacancy slot)
fs: full_slot, tes: typical_empty_slot
ad: arrival_date, ld : left_date, t: container_type.
tg: time group of arrival container(probability
variable).
tc (Cz): the input(container) that located under the
empty_slot (the element of decision for stocking)
Pr: the probability of the time group.
Pr(ad)(tg): the probability of the time group of the
arrival container(tg) with arrival date(ad).
Pr(ld)(tc): the probability of the already storage
container(tc) with the left date(ld).
See Figure: 4. which represents the configuration
of the Paired-Bay method. We will process the
situation as in real-time, so we have 48 slots, 29 slots
are full, and 19 slots are empty (6 * 4 = 24 slots in
every bay, 48 in every Paired-Bay), we will illustrate
three scenarios based on Figure: 4.
The objective function which selects a location of
an arrival container and minimizes the total expected
number of relocation movements can be formulated
as follows:
𝑓
𝑥
𝑃𝑒
𝑟1,𝑡,𝑏
,𝑡𝑔𝑙𝑑𝑡𝑐𝑙𝑑
𝑃𝑒
𝑟,𝑡,𝑏
, 𝑡𝑔𝑙𝑑 𝑡𝑐𝑙𝑑
(1)
..

..

𝑡𝑔 𝑛,𝑎𝑑,𝑙𝑑,𝑡
𝑃𝑒𝑟,𝑡,𝑏

(2)
2.1 Scenarios
For illustration, we assume one Paired-Bay of six
rows and four tires at most, as shown in Figure: 4.
There are 24 locations in the one bay and 48 locations
in the Paired-Bay, each location represented by a
square. In (Bay A), the reserved locations are 15 and
14 locations in (Bay B), vacant locations display
empty squares. The containers are stored in
chronological order according to the time dimension
rule (Farest date is First In) and in the export
according to the (Earliest Date First Out). The
numbers represent their distinct chronological order
in the squares. This method constitutes a flexible
construction for dynamic storage and container
retrieval; the presence of prior storage means that
there is a given configuration of the block, even if
partially, so storing containers based on time implies
that the retrieval sequence process will be well
defined and this, in turn, affects many aspects.
Figure 4: Empty and full slots in the Paired-Bay
Including reshuffling containers if required. So in
this Paired-Bay, we will have 19 empty spaces ready
to receive the new batch of containers. There are
several scenarios in which the method of the store,
departure, and rearrange/reshuffle will be represented
according to our methodology.
2.1.1 Scenario 1 (5 Containers Arrive with
the Unknown Departure Date)
Assuming the configuration shown in Figure 4.
specified on (25-Jan) and five new containers are
arrived on (27-Jan), but the date of departure is
unknown, so they are stored based on the permissible
period of stay of containers in the yard It is from (4 -
7 days) and also can be adapted according to the laws
in force at the station.
In (Bay a), we have container one on location (r2,
t1, Ba) being reshuffled on top of container three on
location Pe(r1, t4, Ba), in this case, this change
provides (4 locations) vacant to store containers (with
the same date), so that the permissible period (for
these containers whose departure date is unknown)
does not exceed the yard (max date) and do not store
the unknown departure date containers on top of
containers have a known departure date, after this
process the (Bay a) considered full, noting that the
remaining vacancies in the (Bay a) It cannot be stored
because the containers under these vacant places have
a known departure date and we cannot put containers
on top of them whose departure date is unknown.
In (Bay b), we will have the same condition that
container 2 in position (r2, t1, Bb) will be reshuffled
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to location Pe(r1, t4, Bb) over the site (r1, t3, Bb)
Full_slot(fs), here also four vacancies were provided
ideal locations for storing the remaining containers
unknown departure date (r2, t, Bb), we will only
operate one location. (Scenario drawing see Figure
(5)). See Figure 5. Scenario 1.
2.1.2 Scenario 2 (5 Containers Arrive with
Known Departure Date)
We assume the arrival of five new containers on (27-
Jan) with known dates, grouped as two containers on
(3-Feb), one container on (1-Feb), and two containers
on (5-Feb). To store the two departing containers on
(5-Feb), either they are stored contrary to the
chronicle range (non-adherence to the methodology)
or in case of searching for a typical location based on
the methodology, rearrange the row(r2) in the bay
(Ba) or in (Bb) is the optimal solution for storing
these two containers. In this case, the
identification/selection of optimal locations for
storing the remaining two containers departing on (3-
Feb) will be clear and relatively fast, which will be on
top of the previous containers (r2, t3 & t4, Ba or Bb).
So the remaining container that has a departure
date (1-Feb) has four vacancies locations according to
the current configuration, which is respectively (r1, t,
Ba, or Bb), but according to the chronic method, the
ideal location for this container is (1-Feb).
However, according to the chronic method, the
ideal location for this container (1-Feb) is (r2, t1, Bb)
being empty. See Figure 5. Scenario 2.
2.1.3 Scenario 3 (Reshuffled-containers
(Reserved Bay))
The re-Reshuffled scenario illustrates how to provide
vacant locations in the event of new containers arrival
with reducing the operating cost. This process is
carried out in the spare time of the equipment.
According to the previous figure (Figure 4.), the
container (24) that existed at the location (r6, t1, Ba)
should move to the Reserved-Bay according to
methodology. Because the methodology cannot deal
with it due to exceeding the permissible period for
staying in the yard and also emptying location (r2, t1,
Ba) to allow storing new containers to which the
balancing methodology applies. The ideal location in
this case for the pre-existing container (r2, t1, Ba ) Is
the position (r1, t4, Ba) according to the time.
This process will provide eight vacant locations,
which are (r2 & r6, t, Ba); likewise, the column (r2 &
r6) in (Bay b) will be rearranged so that the container
(20) (r6, t1, Bb) will be moved into the Reserved-Bay
because it has exceeded the period; this process
provides four vacancies in the column (r6, t, Bb); the
column marked with row r2 is rearranged so the
container (r2, t1, Bb) takes the vacant position (r1, t4,
Bb) so we will get four vacant locations as well.
In general, the rearrangement according to the
Paired-Bay methodology provides perfect vacant
columns (r, t) within the Paired-Bay (4 * 4 = 16),
enabling us to deal with any new storage with any
period because it is empty.
Figure 4: An illustration of the Scenarios
According to the parid-pay methodology and
according to the data in the column (r5, t, Ba) and the
column (r3, t, Bb) with a sequential date 25-27/Jan,
the two columns can be combined according to their
time-range sequence and this provides an ideal vacant
column for storing new containers. See Figure 5.
Scenario 3, 4. Previous scenarios reinforce our
approach, merging two bays facilitates re-mixing and
rearrangement of containers during equipment's spare
time and provides good flexibility as well; as the two
bays will share vacant sites in this situation.
According to (Salebeh, T. & Debo, A., 2020), any
container that has not been decided upon (for
whatever reason), for example not being disbursed on
time, is either moved to another location outside the
yard, or a bay is allocated for containers that are not
disbursed on time, according to the internal laws of
container terminal management, a delay fine is
imposed on these cases.
3 ARTIFICIAL INTELLIGENCE -
ARTIFICIAL NEURAL
NETWORKS
Artificial intelligence brings about change in
management and operation processes. It can reduce
human errors and make operations faster. Therefore,
AI itself is part of a broader process of automation
and improvement of port operations. The vision of
artificial intelligence is represented by rational steps
and organizational boundaries that help to improve
key performance indicators; it serves to achieve
Optimization of the Storage Sites for Export, Inbound, and Reorganize Containers by Timing Location
337
common goals among the parties to artificial
intelligence and promotes beneficial opportunities for
all parties in real-time through prior knowledge of
container movement patterns. We are looking
forward to applying artificial intelligence, especially
neural networks, in addressing the risk and errors of
specifying vacant sites and choosing the optimal
location for the container and this is what we will try
to study in the next research by applying it to the data
of the station (El Qasr El Saghir - Morocco) as a case
study. In this paper, we focus mainly on the proposed
methodology, and the proposal of neural networks in
addressing this problem falls within the scope of
planned future work because of its good ability to
identify patterns and the diversity of methods of real-
time prediction in the ideal empty location. Artificial
Neural Networks (ANNs) are computer programs
whose main goal is to simulate how the human brain
processes information. ANN networks learn (or are
trained) through experience with appropriate learning
models and pool their knowledge by discovering
patterns and relationships in data reference
(Agatonovic-Kustrin & Beresford, 2000).
4 CONCLUSIONS
This study looked at the problem of storing containers
in real-time at the container terminal. The problem
was identified and a two-stage practical solution
approach was proposed. The first phase, dividing the
yard block into dual bays, involves the use of a
proposed methodology for bay timing, while the
time-bound container group approach is used in the
second phase, which specifies the optimal location of
the containers. The results of this study can be
practically implemented by the El Qasr El Saghir
station in Morocco. Through the simple scenarios, the
possibility of the methodology appears in helping
decision-makers store each container and track
storage conditions. When the proposed method is
applied to the reality in the station, it results in large,
repetitive, and diverse data that require collection,
purification, and processing to prove the effectiveness
of the proposed method. In the future paper, we will
process this big data using artificial intelligence to
verify the effectiveness of the method.
ACKNOWLEDGEMENTS
This work was supported by the Laboratory of
Computer Science and System Engineering (CSSE)
in the Faculty of Sciences - Abdelmalek Essaâdi
University.
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