A Review on Remanufacturing Reverse Logistics Network Design and Model Optimization

Round 1

Reviewer 1 Report

Dear authors,

The review provides a nice overview on remanufacturing reverse logistics network design and model optimization. 

Please, improve th quality of the Figure 1 and Figure 2.

Author Response

Thanks for your advice. I have deleted the original Figure 2 and redrew Figure 1 combine the opinions from other reviewers.

Reviewer 2 Report

The paper provides a review of RLND with focuses on remanufacturing and optimization methods. The topic in this paper has been extensively investigated in the literature, and the current work has nothing novelty and offers few contributions in this field. Most importantly, the paper lacks deep insights into the methods and future research agenda, all the findings are actually well reported in the existing literature. The paper is more like the first part of a Ph.D. thesis, but it lacks critical insights that may guide future research in this field, which is of significance for a review paper.

My detailed comments are given as follows:

1, The scope of the review is actually fuzzy, The authors focus on Remanufacturing in RLND, which is considered a main contribution of the research. However, it is not clear to me how this differs from a general RL system since remanufacturing is usually not the only way to deal with the waste products, and it usually needs to be used together with, for example, recycling and disposal, so what is the special reason to only consider one option in the RLND? or is it necessary to do so?

2, In section 2, the authors compare their works with the existing reviews. However, the abbreviations used in table 1 are not properly given and explained. Also, the contributions of this paper are not comparable with some of the important reviews in this field.

3, The methodology part has significant flaws. The most important part of a literature review paper is to keep the clarity and transparency of the sample selection. However, the authors fail to provide a detailed process of how these papers are selected. For example, what keywords are used in the initial search, and how they are combined? How many steps are used for selecting the final sample? What filters and procedures are implemented in each step, and how many papers remain? The research cannot be properly validated without this information. Also, it is not clear why the time frame is set to after 2010, since several good papers were published before 2010 for RLND with remanufacturing, e.g., from EJOR. 

4, The descriptive findings are given, and the basic networks and model analyses are discussed. However, these have been very well reported in the literature, and there is also a lack of deep insights into the mentioned methods. For example, 5.4 only introduces some very basic knowledge in the solution methods, but there is a lack of in-depth analysis to understand how different objectives can be combined with exact and approximation methods, and so forth.

5, Continue with the previous comments, in section 6, which should be named as "Model validation" and it should be a sub-section of section 5. Normally, we do not say a "virtual case" but a "numerical experiment", and also many "so-called case studies" are actually numerical studies in nature, which lack supports of enough real-world data, so this needs to be carefully examined.

6, Also, the paper lacks key analyses of some very important aspects in section 5, like uncertainty issues, technologies, etc. The authors claim that they focus on remanufacturing, but the descriptive findings are very general and are applicable to all RLND, and there is a lack of focus on remanufacturing, e.g., different remanufacturing technologies, regulations in different regions, etc.

7, The gaps and trends in section 7 are extremely poorly analyzed, and I don't think they offer any valuable suggestions for future research agenda. For example, section 7.1 has nothing new ideas, and also it may be misleading since the structure of an RL system is actually contextual, and it is determined by many factors and stakeholders.

8, Section 7.2 says "Different parameters", but it is actually talking about objectives, constraints, and other elements in the model. The authors claim multi-objective and uncertain issues for "future research" in lines 511-513 and lines 524-530, but all of these have been well noted and extensively investigated in the literature. Thus, the section offers nothing new ideas and lacks an in-depth understanding of the basics.

9, The use of new technologies is discussed in a very rough way, and there is no solid suggestions that can be taken for future research, and also the technologies referred to in this paper is just a few of the future-oriented technologies, and there are many more of them, which are not considered in this paper, and also their implications in RL are not well addressed.

10, The paper needs to go through extensive language editing and proofreading, and the current version has several issues.

In summary, even if the paper focuses on a meaningful topic, it lacks novelty and contributions that will help to identify the future research agenda. The literature search is unclear, and there are no in-depth and critical discussions, and all the findings have already been well reported. Besides, the writing needs to be improved, so I don't think this paper can be considered for publication.

I recommend the authors carefully read the following paper:

Reverse logistics and closed-loop supply chain: A comprehensive review to explore the future

Author Response

Thank you for your sincere advice. I have made many modifications in the paper to deal with the problems you mentioned.

1. In Section1, the characteristics of remanufacturing reverse logistics (RRL) are described in lines 57 to 64. The network structure of RRL is different from that of other processing methods, such as hybrid facilities and closed-loop supply chain. In Section 2, the classification of reverse logistics and the main characteristics of remanufacturing are added in line 155.
2. The description of Govindan et al. [9]'s paper at lines 85 to 87 in Section 2 has been modified, and the description of abbreviation in Table 1 has been added.
3. A lot of modifications have been made to Section 3, which describes the whole process of this paper from three steps: Material collection, Descriptive analysis and Category selection. As we can found in the literature review of Section 2, there have been many analyses of papers in previous years, so the last 10 years has been selected as the time range of this paper.
4. In Section 5, we revised the descriptive analysis of the article and added the summary of each section in line 291, 332, 363, 408, respectively.
5. We revised Section 6 as a subheading of Section 5, and modified the description of the case in the article.
6. Remanufacturing techniques are described in Section 5. Since many existing articles did not describe the techniques used in remanufacturing reverse logistics detailedly, we briefly analyzed different remanufacturing techniques in lines 275 through 277.
7. The suggestions of 7.1 is based on the differences of network structures. During the analysis of the paper, many studies had adopted hybrid facilities. Simultaneously, many papers did not consider the possible changes brought by different products and technologies in establishing the network structure, so Paydar and Olfati [42], Zarei et al. [40] and Reddy et al. [41] are selected as three examples.
8. The title name of 7.2 has been revised. The multi-objective and uncertainty mentioned in this section aim to illustrate that there are some special elements to note in the model instead of meaning that these problems haven't been solved. Additionally, the issue of uncertainty is well noted and solved in many papers, but there are still some aspects that have not been considered, such as recycling time and recycling channel, so we present that scholars could consider it in their studies.
9. 4 is an analysis of technology trends. There are few relevant literatures at present. We add some descriptions in line 520.
10. We have revised the article in terms of words and sentences.

Finally, we re-read the paper you mentioned, found the missing problems and made modifications in the paper in line 85 to 87.

Reviewer 3 Report

A review on remanufacturing reverse logistics network design and model optimization

The objective of this paper, which is intended as a synthesis article, is to position remanufacturing as a main feature of reverse logistics in the literature review.

In a first step a literature review of 125 articles on the design and optimisation of the SDR network was identified and analysed according to the network structure, model, solution method and case studies.

 This report presents a summary of the research literature on SDR network design and optimisation in order to have a clear understanding of the state of research in this area and to define the direction for future research.

It presents a synthesis of the papers that have dealt with reverse logistics in terms of the methods and models deployed, the type of networks and the cases studied.

The article is easy to read, but there are some remarks that could improve it.

1. Figure 2 (Number of publications per journal) is not really necessary and is not clear.
2. It is strongly recommended to revise figure 6 to use a more explicit and clearer presentation. The current layout makes it difficult to read/view/understand the information.
3. Figure 7: the comparison cannot be correct between states (India, China, Iran, UAE) on one side and continents on the other (Europe, America)
4. Reverse logistics is considered in the article as a single component with a homogeneous content. What is not real. Reverse logistics concerns heterogeneous components and follows different routes depending on the nature of the products treated, the degree of their dangerousness, the possibility of remanufacturing or not, the cost of reprocessing and the profitability of the operation...
5. The article refers on page 12 to figure 7.2, but this figure does not appear in the article. Also, if there is a figure 7.2, there must be a figure 7.1, hence the need to review this part.
6. How to explain the decrease in figures 1 and 9 in the years 2019 and 2020?
7. Several paragraphs need further treatment e.g. grouping of constraints, resolution methods, cases (by sector, public/private) or (activity - industry/services...) this information is more relevant earlier than information on countries or continents

Author Response

Thanks for your advice. I have made the following modifications to the problems you mentioned.

1. Figure 2 was deleted and analysis in Section 3 was revised based on comments of other reviewers.
2. Figure 6 has been modified to make it easier to view.
3. Figure 7 was redrawn to modify the statistics of mainland and split into specific countries, which were also modified in the paper.
4. The remanufacturing reverse logistics mentioned in this paper refers to the network structure that remanufacturing is considered as a major part. Other operations are also considered in the process of product recycling according to its quality standards.
5. The name error in Section 6.5 is the omission in the revision process of the paper, which has been corrected. The correct name is Figure 8.
6. The material collection in this paper was completed in the first half of 2020, so there are few papers in 2020 in distribution fig.
7. Summary has been added following the descriptive analysis of Section 5, and we revised Section 6 as a subheading of Section 5 based on the comments of other reviewers.

Round 2

Reviewer 2 Report

The authors provided a revision of their manuscript, and some of my previous comments are well addressed, but the others are not. I see the effort the authors made to improve the paper, and the improvement of the literature search in Section 3 is extremely commendable, but some major issues need to be fixed before the paper can be considered for publication. Thus, I would like to re-consider this paper if the authors can carefully think about the following comments in the revision:

1, Please highlight all the changes in the revision.

2, Figure 1 shows that only 2 papers are published in 2020? Are you sure about this search result? This does not comply with the "increasing trend" discussed in lines 223-224. I think this is a big issue, and the authors may provide the date of search to justify this result.

3, Section 5.4 needs to be re-written. In RLND, the solution methods of the optimization problem mean either exact or approximation method. Commercial solvers like CPLEX, Lingo, etc., are mainly used when exact methods are used, like weighting, e-constraint, etc., these are actually the "methods". When the problems become large, approximation methods (heuristics/meta-heuristics) need to be used, and these are, for example, GA, NSGA-II, PSO, etc.

4, Section 6.2 has significant flaws and is very misleading. In lines 603-605, I do question how much the authors understand the subject they reviewed by putting such a claim. The most common method to deal with uncertainty in RLND is stochastic programming, but the authors didn't mention it even if several papers they reviewed used this method. Dealing with uncertainty has been a topic for a long time, and the authors are suggested to read the following paper:

An optimization model for the design of a capacitated multi-product reverse logistics network with uncertainty. European journal of operational research 179.3 (2007): 1063-1077.

Besides, the lines 607-608 seem interesting but need to be better explained, and also the authors need to be careful with the words, for example, it needs to be clear about "recycling" or " remanufacturing" considering the focus of this paper is on the latter one. Besides, lines 609-617 actually offer nothing and should be combined with Section 5.4.

5, Section 6.3, the authors claim "other products like medical products" in line 623 need to be considered in RRL. However, I am not sure how medical products can be REMANUFACTURED! This needs to be explained, and the authors need to provide solid examples and references to support this claim.

6, Section 6.4 needs to be totally re-written. Incorporating new technologies in I4.0/5.0 could be the highlight of this paper, but the authors didn't offer a deep insight into it. The authors are suggested to significantly improve this part to really understand the impacts brought by new technologies, based on which meaning future research may be proposed to guide future research. The following papers may be helpful:

Industry 4.0 Technologies and Their Impact in Contemporary Logistics: A Systematic Literature Review. Sustainability 13.21 (2021): 11643.

The application of Industry 4.0 technologies in sustainable logistics: a systematic literature review (2012–2020) to explore future research opportunities. Environmental Science and Pollution Research (2021): 1-32.

A Systematic Literature Review on Additive Manufacturing in the Context of Circular Economy. Sustainability 13.11 (2021): 6007.

7, The conclusion must be enhanced. First, the main future research agenda needs to be summarized with bullet points. Then, the limitations of this review must be discussed, and as far as I can see, there are several limitations of the current work, so these need to be carefully considered.

The authors must carefully consider these comments and significantly improve their paper in the next revision. 

Author Response

Thanks for your advice. I have made the following modifications to the problems you mentioned.

1. All modifications are marked up using the "Track Changes" function and highlighted in yellow.
2. We added the search date of materials in the 3.1. The collection process of all papers was completed in April 2020, and corresponding modifications have been made in the paper.
3. We have rewritten 5.4 according to the advice from reviewer. The solution methods are divided into two categories, deterministic method and approximate method. The description of commercial solvers was adjusted in the first category.
4. We have modified the contents related to uncertainty. According to the literature recommended by you, we have added the analysis of stochastic programming.The uncertainty of recovery time and recovery channel analyzed in line 607-608 is explained, which refers to the uncertainty in the early collection process of remanufactured products, corresponding changes have been made.The algorithm analysis in line 609-617 was removed and integrated into 5.4.

5. The description of medical products here is not very accurate, the product is not the medical product but the hospital equipment. Corresponding changes have been made.
6. We rewrote 6.4 based on the three papers of Industry 4.0/5.0, the possible influence of I4.0/5.0 on remanufacturing reverse logistics is analyzed from its structure and intelligent remanufacturing technology.
7. The main future research agenda has been summarized with bullet points. We described the findings from network structure, models, and technologies, and the limitation of research method of this paper and the lack of in-depth analysis are added at the end.

Round 3

Reviewer 2 Report

In the revision, the authors have successfully addressed all my previous comments. In my opinion, the paper presents good descriptive findings, and some suggestions, e.g., the impact of I4/5, are very interesting, so I think the paper can be accepted in its current form.

Nevertheless, I recommend the authors improve their writing and establish a deeper understanding of these papers in the future.