The Role of Industry 4.0 and Circular Economy for Sustainable Operations: The Case of Bike Industry

Round 1

Reviewer 1 Report

The topic presented in the paper is valid and still on time. There is still a need for such research works. In the reviewed paper the Authors presented the integration of sustainable production and design decisions of a supply chain in the adoption I4.0 aimed at cost minimization, in which the decision variables include the production rate of ETO components, design time of general components, and time period of advertising and sales promotions.  In my opinion, the paper can be considered for publication, after taking into account the following remarks:

- before the paper publishing, the English should be carefully checked by a professional Native Speaker,

- in the "Keywords" section, the keyword "applied sciences" should be added in order to strengthen the link between the content of the article and the thematic scope of the journal,

- at the moment, we can find in the paper text some acronyms without explanation, e.g. ETO, EOQ , EPQ, and others. The Authors should add an explanation of used acronyms in line with their first use,

- the captions on the figure called "Figure 1. The circular economy system" are too small and because of it they are illegible,

- the case study presented in the paper deal with the bike industry. In the Introduction section, the Authors presented the theoretical background of the research topic presented among others the industry 4.0 problem, then the bike company in Taiwan (in the section called "4. Model Formulation"). It is good, there is a lack of information about the external influence on bike usage and development connected with safety issues as one of the major elements decided about the usage of bikes in reality. These problems are described in the scientific literature in the field, e.g. "External Environmental Analysis for Sustainable Bike-Sharing System Development" doi 10.3390/en15030791; "The analysis of the factors influencing the severity of bicyclist injury in bicyclist-vehicle crashes" doi 10.3390/su14010215. The Authors should mention about these bike usage problems in reality. One short paragraph in the Introduction section will be enough,

- at the end of the Introduction section, the Authors should shortly write what was the main aim of the paper as well as what was contained on each paper section,

- the second section called "Problem description": there is no reason to separate this section. The contents of section 2 should be appended to section 1 "Introduction",

- on all figures in the paper text, where we can find the axis "x" and axis "y", the names of the axis as well as the units should be added,

- in the article, we can find a large number of variables/acronyms/designations. In order to facilitate the reception of the presented content, it would be advisable to add a list of symbols used at the end of the article (abbreviations list),

- there is a lack of discussion dedicated to obtained results. The Authors should add such discussion in line with the reference to the literature items concerning similar results (as a discussion),

- the Authors use numbering: 1,2,3, ... to list information. In scientific articles, numbers are usually reserved for sections and sub-sections. Therefore, bullet points should be marked with a dash or bullet items (not numbers),

- the structure of the paper is badly constructed. The paper should be divided into main sections, and when it is necessary into sub-subsections. Each section and subsection should contain the developed content and can't include only a few sentences. As far now, we can find in the paper text many very short sub-sub-subsections, e.g. like "4.1.1. System Parameters" or "4.1.2. Decision Variables" which construction doesn't fit the requirements for sub-sub-sections. It should be improved in the whole paper (e.g. sub-sub-subsection called "4.1.2. Decision Variables" consists of only from 3 sentences! ),

- the Conclusions section is written in a very general way and should be extended by adding some detailed conclusions from the presented in the paper research.

Author Response

Dear Reviewer

         Thanks for your comment and suggestion. We have made all necessary changes requested by you. Please see the attached file.

Author Response File: Author Response.pdf

Reviewer 2 Report

The paper explores the relationship between Industry 4.0 (I4.0) and circular economy (CE) in the bike company, highlighting the challenge of subassembly costs in achieving resource efficiency and material circularity through I4.0. The study identifies several challenges and recommends a multidisciplinary approach to enable the transition to a circular economy. Additionally, the study considers two situations to improve the average time of the design and sales promotion stages, using a simple algorithm and emphasizes the role of I4.0 in promoting sustainable business performance.

However, there are several areas for improvement. Firstly, the problem description should be part of the introduction section to provide context for the reader. Secondly, acronyms should be explained upon their first use to avoid confusion for the reader. Furthermore, the lack of a literature review section and the need for variable definitions limit the comprehensiveness of the paper. Additionally, Figures 1 and 3 require larger font sizes or clearer lettering for readability. Table 5 also requires adjustments to the spacing of text and column lines.

In addition, Figures 6 and 7 would benefit from including names and units to make it easier to understand the results. An explanation should also explain why cpg is lower in Figure 7. Finally, the authors should consider concluding the study's findings to support their research further.

I suggest accepting the paper with minor changes. The authors should address these issues to improve the paper's readability and comprehensiveness.

Author Response

Dear Reviewer

         Thanks for your comment and suggestion. We have made all necessary changes requested by you. Please see the attached file.

Author Response File: Author Response.pdf

Reviewer 3 Report

The authors explored the concepts of Industry 4.0 and circular economy and presented a case study of an automobile industry. The following comments will further enhance the manuscript:

1. Elaborate Introduction section since it is not presenting the research gap, also enhance the literature review relevant to the research.

2. Extensive language corrections are required, such as in lines 71-72 there is a sentence "In a recent article ..........sustainability science [40-42] doesn't make any sense, it seems incomplete sentence. Line 80, it should be remainder not reminder, etc.

3. Several papers are cited as a bulk like [14-22] and so on; though it doesn't provide any idea about what actually these research studies conveyed, and what new this research work is adding?

4. Define the acronyms at their first usage which is missing all over, such as ETO not defined in the abstract; ESG in line 30, and so on.

5. There is a lot of similarity with your conference article "Circular Economy Policy of Bike Industry- Exploring the Optimal ETO Component under Imperfect Production Processes System"; though it is not even cited in this work.

6. Line 289-290, Sentence should be removed.

7. The results presented from line 290 onwards (including figures) should be moved to results section.

8. Conclusions should be presented in better way which you inferred from the research, not just stating the results. 

Author Response

Dear Reviewer

         Thanks for your comment and suggestion. We have made all necessary changes requested by you. Please see the attached file.

Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Still many improvements are required and comments are not fully incorporated.

Aim and novelty of work is not very much clear

Author Response

Manuscript ID: applsci-2294690

Manuscript Title: The Role of Industry 4.0 and Circular Economy for Sustainable Operations: The Case of Bike Industry

Dear Editor,

Thank you for your letter dated 3 May 2023, informing me to revise the above paper. We appreciate one of anonymous referees for their constructive comments. These comments are valuable and helpful to improve our paper. The revision has addressed these comments, and the responses are listed in “Response to Reviewer Comments”. Moreover, the amendments are highlighted in red in the revised manuscript. Please do not hesitate to contact me if you have any questions.

Sincerely yours,

Ming-Wei Weng

Author Response File: Author Response.pdf