Digital Twins within the Circular Economy: Literature Review and Concept Presentation

Round 1

Reviewer 1 Report

1.     The abstract lacks details of challenges faced by DT in CE.

2.     Introduction section needs modification and updations to include the background information, motivation, and research gap. Also highlight the potential benefit of the work for the readers and industry.

3.     Resolution of images are poor and needs improvement.

Author Response

Many thanks for the feedback. In the file you will find our comments and revisions regarding your feedback.

Author Response File: Author Response.pdf

Reviewer 2 Report

1. The three research questions are not suitable, at least not enough, for an academic literature review. The application scenarios, product life cycle and technology readiness level are important, but they are more about the practical progress of the industry, instead of a critical review of the theoretical progress. 

2. The analysis is somewhat casual. For example, "the PLC is divided into three main stages: Beginning-of-Life (BoL), Middle-of-Life (MoL), and EoL", why is PLC divided into three stages, is there any references? By the way, what is EoL short for? End of life? 

3. Classification of the TRL and classification of 9 R-strategies also need more explanation. Especially what is "R0 Refuse"? Is it reuse?

4. The contents in Table 1 are quite superficial. Maybe it is better to be combined with Table 2. Besides, there are also little information in Table 3, Figure 3 and Figure 4.

5. The Use Case should be more specific about how it is applied and implemented.

6. The conclusions are quite common sense. Besides, the analysis through the whole paper is not very specific and closely related to the key concept "digital twins".

7. Too many abbreviations, which turns into reading barriers. Some abbreviations may be incorrect and confusing, such as the "TLR" in line 98.

Author Response

Many thanks for the feedback. In the file you will find our comments and revisions regarding your feedback.

Author Response File: Author Response.pdf

Reviewer 3 Report

Overall a well conducted SLR into a topical and emerging area of research and practice. As an SLR there is little I can critique in terms of content. The addition of the use case discussion was valuable to clarify a practical application of the DT in CE issue.

While generally well written, I offer some suggestions for editing that I noted while reading the manuscript (number refers to line):

1 - within the circular

14 - the circular

20 - the circular

29 - was established or has been established

32 - among other steps

32 product's

33 "keeping in components" - does not make sense

52 - was conducted

60 - which are two leading databases

111 - a product

Table 1 - Industry 4.0, that may (please check this sentence)

154 - within the refrigerator

178 - BoL

188 - and what?

235 - applications

253 - or future

326 - list's numbers are repeated

339 - just EoL

446 - list's dots are repeated

Author Response

Many thanks for the feedback. In the file you will find our comments and revisions regarding your feedback.

Author Response File: Author Response.pdf

Reviewer 4 Report

There are some comments to improve the paper:

1. The Discussion and outlook section has to be transformed into two separate sections: Discussion; Conclusion.

2. The current text in the Discussion and outlook section is too technical. Try to improve it, as the conclusions drawn are not sufficiently clear, making it difficult for the reader to benefit from it.

3. By the end of the conclusion, the author has to provide the limitations of their research.

4. Under the discussion section, please provide answers to such questions:

4.1. What kind of scientific problem is solved in this research related to the research object?4.2. What are the main gaps in the discussed area based on previous research results?
4.3. What is the novelty of the presented research results?
4.4. What is the usefulness of the proposed research results for practitioners, scientists, and society?

4.5. What are the main theoretical implications of the research results? 

5. The Conclusion section should not have references to literature sources. Please move such a paragraph to the Discussion section. 

6. The English text has to be revised with an advanced Grammarly tool, which helps place articles in the text properly.

7. The title of the article includes "literature review" aspects. However, only 40 literature sources were revised. I think the object of the paper is a conceptual model development, not a literature review. The literature review is the technique that helps to build the conceptual model. I think the authors have to improve the paper's title and highlight in the methodology section that the output of their research is a conceptual model.

8. Please remove "end-of-life decision support" from the keywords as such is not even mentioned in the Discussion and outlook section. Also, the authors do not present any decision-support framework for the reader.

9. Under the Methods and Approach section, please highlight the research design phases, specifying that research starts with a literature review and ends with the conceptual model design.

Author Response

Many thanks for the feedback. In the file you will find our comments and revisions regarding your feedback.

Author Response File: Author Response.pdf

Reviewer 5 Report

Dear Authors

It was with great pleasure that I reviewed your manuscript.

I have just one suggestion.

Table 1 is very large, which can make it a little confusing.

You should split it into two or three tables.

My Best Regards

Author Response

Many thanks for the feedback. In the file you will find our comments and revisions regarding your feedback.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The manuscript is improved. Please pay more attention to the theoretical contribution, the logic and expression of the analysis, and inspiration for further research.

Author Response

Dear Reviewer, than you for your comment. You can find the revised version in the appendix.

Reviewer 4 Report

None

Author Response

Thank you for your feedback!