A Multi-Objective Model for Sustainable Perishable Food Distribution Considering the Impact of Temperature on Vehicle Emissions and Product Shelf Life

Round 1

Reviewer 1 Report

This paper describes the multi-objective VRP model which use an integrated temperature prediction method to estimate product quality and refrigeration energy consumption while accounting for cost, freshness, and emissions in a perishable food distribution system. Adding a heat exchange model to accurately estimate the temperature inside the refrigerated container gives an improvement in comparison to existing models. This paper also utilizes a novel adaptation of the NSGA-II metaheuristics algorithm to solve the MO-SVRP model. Although the model was tested on the data existing in the literature, I think that it offers a solid tool for future works that will use experimental data in real or simulated conditions.

I have noticed only minor technical correction that needs to be made. At Pg 11 Ln 527, temperature units are not written correctly ('263 oK to 269 oK' while it should be '263 °K to 269 °K'). This can be corrected in the final editing of the manuscript and no additional correction from authors is needed.

I congratulate authors for their work and recommend publication of this paper after minor revision as described above.

Author Response

Dear reviewer,

I would like to thank you for taking the time to review my document and sharing your invaluable feedback. Your suggestions helped me to elevate the quality of my manuscript.

Please find my response to your comment below.

 

I have noticed only minor technical correction that needs to be made. At Pg 11 Ln 527, temperature units are not written correctly ('263 oK to 269 oK' while it should be '263 °K to 269 °K'). This can be corrected in the final editing of the manuscript and no additional correction from authors is needed.

Necessary corrections were made in the results section.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments

1. Though the work is suitable for this journal and presents an adequate research structure, I suggest the authors to expand the introduction by including practical implications.
2. Please confirm the citation format of some previous studies (Amorim et al., 2012; Hsu et al., 2013; Ghezavati et al., 2017, and son on) in Literature Review section.
3. Please specify the structure of Figure 3. It is not easy to understand this MO-SVRP model in the present version.
4. Please indicate the basis for the order of literature display in Table 1. Further, what does “x” mean?
5. What are the contents of theorems 1 and 2 in Section 3.1?
6. The definition for symbol F is difference between (11) and (13). Please check.
7. The References section seems incomplete. Most of them lack pages, issues or volumes. Please check.

Author Response

Dear reviewer,

I would like to thank you for taking the time to review my document and sharing your invaluable feedback. Your suggestions helped me to elevate the quality of my manuscript.

Please find my responses to your comments below.

1. Though the work is suitable for this journal and presents an adequate research structure, I suggest the authors to expand the introduction by including practical implications.

Introduction section was revised to reflect your comment.

2. Please confirm the citation format of some previous studies (Amorim et al., 2012; Hsu et al., 2013; Ghezavati et al., 2017, and son on) in Literature Review section.

Necessary changes in the citation format were made.

3. Please specify the structure of Figure 3. It is not easy to understand this MO-SVRP model in the present version.

Assuming that you are referring to figure 1, the structure of this figure was explained in section 3.

4. Please indicate the basis for the order of literature display in Table 1. Further, what does “x” mean?

The order of literature and symbol “x” were explained in the section 2.

5. What are the contents of theorems 1 and 2 in Section 3.1?

Theorems 1 and 2 are referred to appendix A in text.

6. The definition for symbol F is difference between (11) and (13). Please check.

Symbol F was changed to “EC” in equation 11.

7. The References section seems incomplete. Most of them lack pages, issues or volumes. Please check.

References section was revised to reflect your comment.

Author Response File: Author Response.pdf

Reviewer 3 Report

This article deals with planning sustainable distribution operations for perishable and temperature-sensitive products that need refrigeration in storage and transportation phases.

The authors provided a meta-heuristic NSGA-II approach to solve a Multi-Objective routing problem involving product safety/quality (freshness), transportation costs, and carbon emissions.

They clarified how multiple stops along the delivery tour mean raise of temperature due to doors opening. At the same time, fully loaded trucks increase the utilization of the fleet capacity and reduce overall transportation costs and related carbon emissions.

The analytical and empirical methods to assess freshness and carbon emissions are fairly quote by the literature and appropriate.

The vehicle routing formulation, despite well-known, is correct.

Also, the description of the NSGA-II methodology and the rules followed to swap, fix, and select chromosomes are well reported.

The paper is well written and easy to follow either for common readers less expert in mathematical programming, which is good in this context given the multidisciplinarity of the Journal.

I encourage the publication of this article.

Nevertheless, four main concerns should be addressed and related aspects handled or at least discussed in the revised paper:

1. Literature review. As the paper deals with multi-objective formulation for perishable products distribution, I would encourage to widen the research of literature involving those contributions that solved multi-objective problems along other stages of temperature-sensitive supply chains. Among those, my suggestion is to focus on the ones that use temperature conservation as the main driver of the problem.
2. Numerical application. While the methodology is well presented and validated through the Solomon testbed, I encourage the authors to apply their method to a broader case study focusing or comparing the performance of different supply chains, products, weather conditions, road networks. A tailored sensitivity analysis should be set up with the purpose of gathering recommendations and practical implications for managers and food supply chain stakeholders. Charts and graphs of the obtained results could increase the contribution of this research significantly. As their meta-heuristic approach is quick and efficient a wider case study could be a more effective way the propose their contribution.
3. Objectives trade-off. I am wondering whether the method chosen from the literature (i.e. [32])to select a "final solution" is still consistent and should then merely reused. In my opinion, it is a static and not tailored way to choose among solutions, as it does not take into account the nature of the solutions and their meaning (say, it could be costs, freshness, but also profit or water consumption with no differences at all). I would suggest elaborating on a dynamic way to choose among solutions that considers the weight the solutions have depending on the set of parameters they build on. This policy could change with the climate/weather conditions (cold or warm), the road-network conditions, or simply the geography of the network or the costs of fuels. As we know, these parameters dynamically change and such change could lead the choice of the best compromise among the solutions. For reference see at "Picking efficiency and stock safety: a bi-objective storage assignment policy for temperature-sensitive products".
4. A discussion section on the results obtained from the case study could be of merit. It also would give the opportunity to underline synergies and integrations with other research.

Author Response

Dear reviewer,

I would like to thank you for taking the time to review my document and sharing your invaluable feedback. Your suggestions helped me to elevate the quality of my manuscript.

Please find my responses to your comments below.

1. Literature review. As the paper deals with multi-objective formulation for perishable products distribution, I would encourage to widen the research of literature involving those contributions that solved multi-objective problems along other stages of temperature-sensitive supply chains. Among those, my suggestion is to focus on the ones that use temperature conservation as the main driver of the problem.

The literature review was expanded to reflect your comment.

 

2. Numerical application. While the methodology is well presented and validated through the Solomon testbed, I encourage the authors to apply their method to a broader case study focusing or comparing the performance of different supply chains, products, weather conditions, road networks. A tailored sensitivity analysis should be set up with the purpose of gathering recommendations and practical implications for managers and food supply chain stakeholders. Charts and graphs of the obtained results could increase the contribution of this research significantly. As their meta-heuristic approach is quick and efficient a wider case study could be a more effective way the propose their contribution.

The main purpose of this study is to present a methodology to accurately measure and optimize the sustainability goals in the distribution of perishable products. As the importance of practical implication is inevitable, we highlighted the application of this research over the case study in the future work section.

 

3. Objectives trade-off. I am wondering whether the method chosen from the literature (i.e. [32])to select a "final solution" is still consistent and should then merely reused. In my opinion, it is a static and not tailored way to choose among solutions, as it does not take into account the nature of the solutions and their meaning (say, it could be costs, freshness, but also profit or water consumption with no differences at all). I would suggest elaborating on a dynamic way to choose among solutions that considers the weight the solutions have depending on the set of parameters they build on. This policy could change with the climate/weather conditions (cold or warm), the road-network conditions, or simply the geography of the network or the costs of fuels. As we know, these parameters dynamically change and such change could lead the choice of the best compromise among the solutions. For reference see at "Picking efficiency and stock safety: a bi-objective storage assignment policy for temperature-sensitive products".

As we agree that the solutions can be impacted by the dynamics of the parameters, hence, the sensitivity of the solutions to model parameters was illustrated in the sensitivity analysis section which represents the changes in the routing plans with respect to the dynamics of the parameters. However, the limitations of the presented approach were discussed in the results and discussion section in response to your concerns.

 

4. A discussion section on the results obtained from the case study could be of merit. It also would give the opportunity to underline synergies and integrations with other research.

The alignments of the results with the literature were represented for the sensitivity analysis section.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The authors seem to have responded to most of my earlier comments. I only have several questions and suggestions as follows.

1. In my opinion, the presentations of Theorem 1 and 2 are inappropriate. Are they equations? Is Appendix A the proof of them?
2. Line 72 and Table 1, please delete “X.”.
3. Line 125 and Table 1, please delete “S.”.
4. Line 136 and Table 1, please delete “F.”.

Author Response

Dear reviewer,

 

I would like to thank you again for reviewing this paper in the second round. I believe that your comments and feedbacks elevate the quality of this paper. Here are my responses to your comments.

 

1. In my opinion, the presentations of Theorem 1 and 2 are inappropriate. Are they equations? Is Appendix A the proof of them?

The word “theorem” was removed from the paper, and detailed derivation of the equations was referred to.

 

2. Line 72 and Table 1, please delete “X.”.

“X.” was deleted from line 72 and Table 1.

 

3. Line 125 and Table 1, please delete “S.”.

“S.” was deleted from line 125 and Table 1.

 

4. Line 136 and Table 1, please delete “F.”.

“F.” was deleted from line 136 and Table 1.

 

Author Response File: Author Response.pdf

Reviewer 3 Report

Dear Editor,

The authors addressed partially to my suggestions and modified the original manuscript just in a few and small parts. 

Even though I am not completely satisfied with the revisions provided, the method is fairly explained and despite a limited contribution given to the literature, this research is interesting and well written and the paper deserves to be published. 

Author Response

Dear reviewer,

I would like to thank you again for taking the time and effort to review this paper in the second round. Here is my response to your comment.

The authors addressed partially to my suggestions and modified the original manuscript just in a few and small parts.

Even though I am not completely satisfied with the revisions provided, the method is fairly explained and despite a limited contribution given to the literature, this research is interesting and well written and the paper deserves to be published.

I believe that your constructive criticisms and feedbacks not only helped to elevate the quality of this paper but also it would be valuable advice for the future direction of this research and the research team.

Author Response File: Author Response.pdf