How to Make Augmented Reality a Tool for Railway Maintenance Operations: Operator 4.0 Perspective
Round 1
Reviewer 1 Report
The topic is relevant and appropriate for the journal Applied Sciences. However, I think some sections need improvement. Here follow some points that need further attention:
- Abstract: The abstract should be improved to more clearly state the purpose, methodology, results, conclusion, etc. In the current form, there is too much general content and the abstract lacks description of the results and findings of the study.
- Introduction: the authors mention that maintenance is an important part of asset management, which is correct. Many studies often overlook the more holistic view. However, please highlight this in a bit more detail. Nowadays, studies strongly advocate that maintenance is a part of asset management, which is also an important part of Industry 4.0. It is suggested that the authors include some recent work to support this:
Maletič, D., Maletič, M., Al-Najjar, B., & Gomišček, B. (2020). An analysis of physical asset management core practices and their influence on operational performance. Sustainability, 12(21), 9097.
Gavrikova, E., Volkova, I., & Burda, Y. (2020). Strategic aspects of asset management: An overview of current research. Sustainability, 12(15), 5955.
Although the introduction section is well written, it is suggested that more relevant background information on the topic should be included. In this way, the authors could additionally explain how their research fills gaps in existing research. It could also add to the scientific soundness.
- Theoretical background: in some places statements are made without proper foundation or references (page 5, line 169-178; e.g. the authors say "AR is considered key for improving the transfer of information from the digital to the physical world of the smart operator."; although the statement is obvious, some previous studies probably imply this based on their results). The same comment applies to section 2.4.
- Case study: what was your sampling strategy? What criteria did you use to select Dutch Railway company (NS)? How can you justify using only one case for the verification of the proposed framework?
- There is a lack of proper discussion of the research results in comparison to other research. Please interpret your findings in light of what was already known.
- Theoretical and Practical Implications should be described in more detail. How your findings contribute to the understanding of the research problem under investigation and what managers can learn from your findings should be emphasized more. Future research should also be highlighted.
Author Response
"Please see the attachment"
Author Response File: 
Author Response.docx
Reviewer 2 Report
The manuscript deals with an applied topic and presents an AR-based tool used to optimize railway maintenance operations. The article is well written and structured, the research question is mainly derived from practical concerns. There are some points which I would like to mention and which the author team should consider in a revised version of the manuscript:
- The term “flexible” could be avoided in the title. I do not see any advantage in using this attribute. I would expect that digital tools nowadays guarantee flexibility. If the term is taken out of the title, it could also be replaced at several passages throughout the manuscript.
- What I do miss, is a bit more stability in the literature body. AR is not only used in maintenance operations, but also in several experimental settings. It helps to standardize and make workflows more user-friendly and efficiently. The connection between AR interfaces and scientific applications should be emphasized in the introductory chapter. Keil et al., for instance, programmed an interface used to standardize the conduction of an experiment on spatial cognition:
Keil, J., Edler, D., Dickmann, F. (2019). Preparing the HoloLens for User Studies: An Augmented Reality Interface for the Spatial Adjustment of Holographic Objects in 3D Indoor Environments. In: KN - Journal of Cartography and Geographic Information, 69 (3), pp. 205-215. https://doi.org/10.1007/s42489-019-00025-z
Another practical example of using AR interfaces for the maintenance of underground utilities was recently provided by Stylianides et al.
Stylianidis, E., Valari, E., Pagani, A. et al. Augmented Reality Geovisualisation for Underground Utilities. PFG 88, 173–185 (2020). https://doi.org/10.1007/s41064-020-00108-x
- Could you be a bit more precisely about the empirical part of the case study (chapter 4). What exactly were the aims of this study? And how did you operationalize your aims empirically? Could you provide numbers? How many participants were involved?
- If you extended chapter 4 (based on the proposals made in point 3), you would also have to adjust your conclusion chapter. This is well-structured in its current state, but please provide more information based on a more transparent case study.
Author Response
"Please see the attachment"
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Dear authors,
I thank you for considering my comments. The quality of the manuscript has been improved. I noticed that some of the newly added references in the reference section of the manuscript are not spelled correctly. For example:
Reference no. 2:
Al-najjar B, Gomišˇ B. An Analysis of Physical Asset Management Core Practices and Their Influence on Operational 668 Performance. 2020;
Please correct to:
Maletič, D., Maletič, M., Al-Najjar, B., & Gomišček, B. (2020). An analysis of physical asset management core practices and their influence on operational performance. Sustainability, 12(21), 9097.
Reference no. 3:
Gavrikova E, Volkova I, Burda Y. Strategic Aspects of Asset Management: An Overview of Current Research. 2020;9–11. 6
Please correct to:
Gavrikova, E., Volkova, I., & Burda, Y. (2020). Strategic aspects of asset management: An overview of current research. Sustainability, 12(15), 5955.
Reference no. 10:
Hansen LH, Wyke SS, Kjems E. Combining Reality Capture and Augmented Reality to Visualise Subsurface Utilities in the 683 Field Combining Reality Capture and Augmented Reality to Visualise Subsurface Utilities in the Field. 2020;(November).
Please add the conference name:
37tℎ International Symposium on Automation and Robotics in Construction (ISARC 2020)
Please also check the other references as well.
One other minor comment:
Page 16, line 615: „Many companies are considering implementing AR solutions to their maintenance operations and are willing to perform several experiments using the technology.” Have you observed this in other studies or technical reports? Please include a reference to support your statement.
The authors did a good job in revising the manuscript. I have no further comments.
Author Response
"Please see the attachment"
Author Response File: Author Response.docx
Reviewer 2 Report
The author team prepared a revised version of the manuscript in which all points mentioned in the first review round are adressed. The points are much clearer now. Accordingly, I would recommend to accept the new version.
One additional comment I would like to make, as the leading author is a PhD candidate: Please go a bit more into detail in the response letter in your future research. The idea behind the letter is not only to summarize the changes 'technically' but also to dicuss the thoughts behind the changes. This would improve the process even more. Good luck for your interesting research topic!
Author Response
11th of March 2021
The authors would like to thank the reviewer for the feedback.
As the leading author, I thank you for providing feedback on the response letter.
Sincerely,
On behalf of the authors,
Sara Scheffer, PhD candidate
