HUs Fleet Management in an Automated Container Port: Assessment by a Simulation Approach
Round 1
Reviewer 1 Report
The research paper is well structured: it begins with introduction and continues with the description of the data that were used in the study, the results and the conclusions. However, the paper should have a “Literature review and research framework” chapter.
The authors try to identify intelligent solutions in order to improve the port performance by increasing productivity and reducing logistic times. The main goal of the paper is to evaluate the impact of the automation in a container port.
The motivation and conclusions of the paper are adequate.
Author Response
The authors have taken your suggestion about the literature review by adding a new chapter
Reviewer 2 Report
This paper examines a HUs fleet management with a simulation approach. The following should be considered in this paper:
1- The introduction is very brief. It does not have new sources for explanations and the innovation of this research is not clear.
2- The structure of the article is not specified at the end of the introduction.
3- Does the article not have a literature review?
4- It is better to give more references to the articles of recent years, especially the articles of 2023 and 2022.
5- The research gap is not mentioned for this research. A research gap table should be provided.
6- Images must define something specific. For example, Figure 4 is not transparent at all, and there is no need for it. What is the special feature of this shape? These types of images are more useful for newspaper articles and not for scientific articles. Figure 5 is the same.
7- The conclusion section is insufficient and should be further dissected. The limitations of the research are not mentioned in it.
8- If similar studies have been conducted in this field, it is better to compare the simulation results with previous studies.
Author Response
- The introduction has been changed; some references have been added in order to make the section more complete and solid. The importance and the innovation of the research has been better clarified.
The paper aims to underline the impacts of automatic HUs in the performance of a port by using a simulation approach. In the scientific literature there are many papers dealing with port automation but, to our knowledge, there is no modeling approach that uses graph theory and cost analysis to demonstrate the importance of automated HUs.
- Now the structure of the paper is specified in the introduction
- The chapter of literature review has been added.
- References of recent years have been introduced in the paper.
- The research gap is now discussed in the paper. In the sector literature there are studies that compare the performance of automated and non-automated ports; however, the comparison can be questionable as the contexts in which the port nodes operate are different. No research has been found that projects traditional terminals towards automation and therefore allows to understand how the efficiency of a port changes if the traditional structure is partially or totally replaced with automation. The paper makes it possible to compare the performance of a port both in the case in which the containers handling takes place with ordinary means and in the case in which these are partially or totally replaced with automated HUs.
- The figures have been removed
- The conclusions have been improved by including research limitations and future developments.
- The authors found no research where the results can be compared with the results of this research. No scientific research has been found that uses a simulation approach to demonstrate how port performance changes if traditional handling equipment is replaced by partially and fully automated handling equipment.
Reviewer 3 Report
There is already a large accumulation of this type of research, and the novelty of this paper is unclear. One factor may be that previous studies have not been adequately reviewed. The structure of the paper itself is also different from the norm and will require considerable revision for improvement. Unfortunately, for the above reasons, there is no choice but to recommend that the manuscript be resubmitted for publication.
The number of paragraphs is also quite concerning.
Author Response
The innovation of the paper is now better clarified. The paper has been modified with the aim of improving it and making it more solid.
Reviewer 4 Report
Major revision is needed:
1) In the input dataset, what is the occupancy of the yard? This should be better discussed.
2) More sensitivity analysis must be applied on changing input parameters.
3) More analysis can be done for alternative configurations.
4) Authors mention about energy consumption and equipment planning. Following studies focus on equipment and yard planing. Authors can cite and discuss in the paper:
2019. A review of energy efficiency in ports: Operational strategies, technologies and energy management systems. Renewable and Sustainable Energy Reviews, 112, pp.170-182.
2023. The Integrated Scheduling Optimization for Container Handling by Using Driverless Electric Truck in Automated Container Terminal. Sustainability, 15(6), p.5536.
2021. Optimal energy management and operations planning in seaports with smart grid while harnessing renewable energy under uncertainty. Omega, 103, p.102445.
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Author Response
- At the start of simulation, it is assumed that the yard is completely empty.
- This type of analysis requires specific in-depth study which must necessarily be treated at a different time with another research. This suggestion has been introduced in the paper and we propose to develop it in future research.
- Other analysis could be done for alternative scenarios. Unfortunately, to avoid the paper being too long, only some analysis are reported in the paper. However, this has now been underlined in the limitations of the research and the future developments in the conclusions.
- In the literature review chapter, the relationship between automation and efficiency has been considered and these works have been discussed.
Round 2
Reviewer 2 Report
The authors have made the requested corrections correctly. The article is acceptable in its current state.
must be improved.
Author Response
thank you for appreciating the work we have done
Reviewer 3 Report
Based on the revisions, my opinion did not change significantly. That is "There is already a large accumulation of this type of research, and the novelty of this paper is unclear. The structure of the paper itself is also different from the norm and will require considerable revision for improvement. Unfortunately, for the above reasons, there is no choice but to recommend that the manuscript be resubmitted for publication.".
No major problems.
Author Response
We are sorry for not fulfilling your requests. We believe that in the current version the gap in the literature and the contribution we want to make are clear
Reviewer 4 Report
Authors give me some answers in reply document. However, they did not conduct any proper changes in the paper. This has to be done. Otherwise, this paper cannot be published in my eyes.
To comment authors responses:
1) "At the start of simulation, it is assumed that the yard is completely empty." This is very misleading. There is no empty yard in practical setting. All yards have some occupancy at the begining. There are two options for authors (i) either you generate data where %80 of yard is occupied at the begining and rerun all test (ii) or you find the warm start period (until 80% occupuancy) and remove that simulations from your results, and represent results.
2) You have to conduct sensitivity analysis to understand robustness of your results. This cannot be left for future research.
3) There are other papers which focus on yard management and yard trucks. You can cite and discuss: https://doi.org/10.1016/j.trb.2018.03.009 ; https://doi.org/10.1016/j.trb.2016.04.011
Author Response
1) we share the observations made by the reviewer on the yard occupancy. But we want to clarify that the hypothesis of an empty yard, during the simulation, is justified by the fact that the status of the yard does not affect the results of the work. The objective of the paper is aimed at understanding how many containers are stored by the HUs in the reference period; it is important to understand how much the yard occupancy has increased, and not by how many containers there are in the total. For this reason, the number of containers present at the start of the simulation has no effect the results and for simplicity we have set it to zero. If we were to analyze the status of the yard, we would have to consider other phenomena such as, for example, the containers that are picked up for shipments; clearly, we have tried to develop only some aspects and therefore we have made a hypothesis of the empty yard which clearly does not affect the results because the objective of the work is to understand the increase of containers in the yard.
2) A sensitivity analysis has been elaborated and reported in the text to understand robustness of our results
3) the suggested references have been discussed and cited in the text
Round 3
Reviewer 4 Report
The paper can be accepted.
One remark to authors' comment on yard occupancy: There are ports around the world where yard occupancy limits the number of new containers to be stored in some yard sections. Therefore, it constrains the problem and it is relevant. Still, I accept authors assumption to consider it empty.
