Industrial Insights on Digital Twins in Manufacturing: Application Landscape, Current Practices, and Future Needs

Round 1

Reviewer 1 Report

1) The abbreviation BEP for break even point should be explained when it first appears to improve the readability of the article

2) Can the spreadsheet of page 14 be horizontally scrolled, as it may result in a poor reading experience for readers

Minor revision is requried to correct some grammar or type error.

Author Response

Dear Reviewer,

We thank you for the insightful feedback you have provided, along with the time you have generously dedicated to the review of our paper.

Your comments and suggestions have been carefully considered and incorporated into the revised version of our manuscript.

In response to your observations, the explanation of the BEP has been transposed to the first point of its mention, thus providing clarity to the reader at the initial stage of introduction to the concept.

Following your advice, we have also rotated Table 2 located on page 11, believing that it now delivers an improved reading experience.

To maintain transparency and facilitate the evaluation process, we have opted to utilise the 'track changes' function whilst revising our manuscript. This way, all the reviewers will be able to directly observe the modifications that have been made.

Reviewer 2 Report

The paper is very well written, informative and a pleasure to read. The scientific approach is systematic, detailed and well explained.
The quotes from industry partners make the paper particularly compelling.
The finding that DT can also give valuable results for industrial processes, such as supply chain management, may be a new insight for some.
However, the paper is also written in a very detailed way, and therefore a bit long, so be more concise in the future if you want to reach industry readers. After all, you may know the manager's disease: "I don't have time."

Regarding the editorial part, in Figure 1 the value for the defense is missing or not readable.
Below there is another small structural problem. They always show a figure first and then comes explanation. Actually, you should do this by briefly introducing a topic, for example the use of the BEP, then showing the graph, and finally bringing the explanation or interpretation. In general, this approach works quite well for the readability of your paper, but with Figure 4 it is a bit difficult. Line 249 to 256. You first introduce the BEP without explaining it. There is also no reference to chapter 4.2.3. At this point I would rearrange the paper a bit and explain the BEP first, then show the graph and then interpret it. Also, the graph 4 needs to have the abscissa and ordinate explained. Both are not clear. The ordinate must be months, not years as written in the text.
Otherwise, everything is good so far.

Further good luck with the work and this exciting topic.

Author Response

Dear Reviewer,

We thank you for your feedback and the substantial time you have dedicated to the review of our manuscript.

Your comments and suggestions have been considered and incorporated into the newly revised version of our paper.

In our commitment to enhancing the paper's coherence and readability, we have undertaken a comprehensive restructuring of the entire manuscript. We believe this adjustment will provide an improved and more engaging reading experience for all.

Heeding your advice, we have advanced the explanation of the BEP to its first instance of mention, aiming to clarify its meaning at the point of introduction.

Similarly, your observation has prompted us to refine the description accompanying Figure 4. 

Reviewer 3 Report

The paper contains minor shortcomings. In order to improve, the following should be considered:

1.      The authors should clearly answer to research question no.1. The authors should clearly highlight and detail the research results.

2.      The authors should clearly answer to research question no.2. The authors should clearly highlight and detail the research results.

Author Response

Dear Reviewer,

We thank you for your feedback and the considerable time you have dedicated to the review of our manuscript.

Your comments have been diligently taken into account and implemented in the newly revised version of our paper.

In compliance with the editor's suggestion, we have relocated the answers to our research questions to the discussion section. Moreover, the answers to RQ1 and RQ2 have been rewritten. To improve the clarity and readability of the responses, providing a more direct and comprehensive understanding for our readers.

Reviewer 4 Report

This manuscript presents the results of a survey and interviews regarding digital twin technology. The main concerns of the Reviewer are:

·       -Samples are too small and some of the statements in the manuscript are generalised based on this. For instance: “…This factor has been mentioned 4 times in 3 interviews. This suggests that the participants of the study see the DT as a way to increase the understanding of the asset and how it behaves, …” only 3/14 participants mention this, and is generalised.

·       -Same results are presented in different ways, but they do not add any new information/insights.

·       -The discussion is too general, it does not add any new/valuable information.

·       -Authors should contribute to the field, not only by presenting the results of the survey and interviews. For example, Authors claims: “The key contribution to knowledge is the capture of the DT paradigm and its implementation together with novel and innovative practices and procedures that are both in existence and development within the industry.” Such contribution is not presented.

-Do not use contractions.

-Reduce redundancies, in particular at the beginning of each Section.

Author Response

Dear Reviewer,

We thank you for your feedback and the significant time you have dedicated to the review of our manuscript.

Your comments and considerations have been taken into account and integrated into the revised version of our paper.

We wish to address the geographical focus of our research. Throughout the manuscript, we have emphasised on several occasions that the companies participating in the interviews and the online survey are UK-based. This point has been explicitly presented as a limitation in our conclusions. To ensure clarity on this matter, we have now added a mention of it in the abstract and further emphasised it in the conclusion.

Despite this geographical limitation, we believe that our sample size, comprising 99 responses in the online survey and 14 interviewees, is aligned with the norms of current literature. Importantly, this research presents the direct perspectives and needs of industry professionals, providing an element of practical insight that is highly sought after in the scientific community.

In response to your observations, we have condensed the results section of the interview, and have decided to omit insignificant numbers. By doing so, we now exclusively report the most salient and relevant findings, thereby improving the readability of the results.

We have also addressed instances of repetition throughout the manuscript, which has led to a substantial rewrite and restructuring of the paper. To enhance readability, we have converted some portions of textual information into illustrative images, believing this to provide a more engaging and comprehensible presentation.

Moreover, we have rewritten the section detailing our contribution to the field of knowledge in the introduction.

The authors decided to submit this manuscript to the special issue titled "Digital Twins for Complex Systems" after consultation with the issue's editor regarding its scope. We firmly believe that our article aligns well with the theme of Digital Twins, as outlined in this special issue.

Furthermore, upon reviewing the first two articles published in this special issue, we found no explicit reference to the topic of cognitive computing. Nonetheless, a central takeaway from our article is the identified need for further research into the domain of the Federation of DTs. It's worth noting that we have already published a systematic literature review on cognitive DTs. The latter concept is one of the main technologies enabling the Federation of DTs. This current manuscript, based on surveys and interviews, underscores and reinforces the call for research in the area of cognitive DT, thereby contributing meaningfully to the realm of cognitive computing. This link has been explicitly mentioned in a paragraph in the conclusion.

Given these considerations, we contend that our paper not only holds relevance for the special issue on Digital Twins for complex systems but is also generally pertinent to the journal's focus on big data and cognitive computing.

Round 2

Reviewer 4 Report

Thank you for improving the manuscript and addressing th comments.

Author Response

Dear Reviewer,

We thank you for the significant time and expertise you have dedicated to the review of our manuscript.