Framework for Dynamic Circular Economy in the Building Industry: Integration of Blockchain Technology and Multi-Criteria Decision-Making Approach
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsSummary/Contribution: The work develops a theoretical framework for a digital platform ecosystem that merges blockchain technology and multi-criteria decision-making to enable dynamic circular economy practices in the building industry. The authors address the information management, cross-sector documentation, and sales operations issues that hamper viable circular economic models. The framework promotes transparency, traceability, and dynamic circular economy practices by using blockchain technology to document and trace used and built-in materials and products and a multi-criteria decision-making approach to rank and select optimal options. This study lays the groundwork for a digital platform ecosystem that facilitates the transparent flow of materials throughout their lifecycle and enables informed decision-making based on detailed material analyses.
Comments/Suggestions:
1. Provide more context and explanation for concepts and acronyms. For instance, explain what CE (circular economy), BCT (blockchain technology), BIM (building information management), and UMP (used/built-in materials and products) stand for and their significance in the context of the building industry.
2. The paper could benefit from providing more specific examples or statistics to support the statements made about the level of waste production and unsustainable resource use in the building industry. This would add credibility to the arguments being presented.
3. Instead of listing multiple definitions of CE without further analysis, it would be helpful to provide a concise summary or synthesis of these definitions to give readers a clear understanding of the concept. This would also eliminate the need for referencing each definition individually.
4. When introducing the lack of understanding and examination of circular product design, end-of-life considerations, and building design in previous research, it would be valuable to briefly explain the importance of these aspects within the context of CE. This would help readers understand the specific gaps that need to be addressed.
5. The mention of the "Digital data-driven concept" (D3c) developed by Mêda et al. [27] and the "Circular Digital Built environment framework" introduced by Cetin et al. [5] could be expanded upon. It would be beneficial to briefly explain the key features or components of these frameworks and how they contribute to the adoption of CE in the building industry.
6. In the paragraph, where digital technologies are discussed, it would be helpful to provide a concise explanation of how these technologies, such as BIM (building information modeling) and BCT (blockchain technology), can support the transition to a circular building industry. This would provide more clarity regarding the role of digital technologies in the context of CE.
7. When discussing supply chain-related barriers, such as transparency, traceability, collaboration, and lack of trust, it would be helpful to explain how these factors specifically affect the implementation of CE in the building industry. Providing examples or case studies that illustrate these challenges would enhance the readers' understanding.
8. Expand on the mention of carbon footprints, technology, product recovery, and the flow of return goods as supply chain-related barriers. Provide a brief explanation of each barrier and its impact on CE adoption in the building industry.
9. Consider discussing the role of regulations and policies as potential barriers to CE adoption in the building industry. This could include challenges related to existing regulations that may not align with CE principles or the need for supportive policies to incentivize sustainable practices.
a. https://ieeexplore.ieee.org/document/9970534
b. https://ieeexplore.ieee.org/document/8328737
Comments on the Quality of English Language
Can be improved
Author Response
1. Provide more context and explanation for concepts and acronyms. For instance, explain what CE (circular economy), BCT (blockchain technology), BIM (building information management), and UMP (used/built-in materials and products) stand for and their significance in the context of the building industry.
Explanation of concepts have been included in Introduction (See lines 55-59, 80-87, 91-95).
- The paper could benefit from providing more specific examples or statistics to support the statements made about the level of waste production and unsustainable resource use in the building industry. This would add credibility to the arguments being presented.
More statistics regarding the level of waste production and unsustainable resource usage have been included in Introduction (See lines 39-50).
- Instead of listing multiple definitions of CE without further analysis, it would be helpful to provide a concise summary or synthesis of these definitions to give readers a clear understanding of the concept. This would also eliminate the need for referencing each definition individually.
A synthesis of these definitions has been included (see lies 152-160), however, the definitions are still kept in the manuscript as they are believed to have significance.
- When introducing the lack of understanding and examination of circular product design, end-of-life considerations, and building design in previous research, it would be valuable to briefly explain the importance of these aspects within the context of CE. This would help readers understand the specific gaps that need to be addressed.
Circular product design, end-of-life considerations, and building design have been addressed in section 2.1.1 (see lines 170-182).
- The mention of the "Digital data-driven concept" (D3c) developed by Mêda et al. [27] and the "Circular Digital Built environment framework" introduced by Cetin et al. [5] could be expanded upon. It would be beneficial to briefly explain the key features or components of these frameworks and how they contribute to the adoption of CE in the building industry.
Digital data-driven concept (D3c) and Circular Digital Built environment framework have been -explained in detail (See lines 184-193, 196-205).
- In the paragraph, where digital technologies are discussed, it would be helpful to provide a concise explanation of how these technologies, such as BIM (building information modeling) and BCT (blockchain technology), can support the transition to a circular building industry. This would provide more clarity regarding the role of digital technologies in the context of CE.
A concise explanation of how BIM and BCT can support the transition to a circular building industry have been included in section 2.1.1 (See lines (217-228).
7. When discussing supply chain-related barriers, such as transparency, traceability, collaboration, and lack of trust, it would be helpful to explain how these factors specifically affect the implementation of CE in the building industry. Providing examples or case studies that illustrate these challenges would enhance the readers' understanding.
Examples regarding supply chain-related barriers, such as transparency, traceability, collaboration, and lack of trust that affect the implementation of CE in the building industry have been included in 2.1.2. (See lines 278-306)
- Expand on the mention of carbon footprints, technology, product recovery, and the flow of return goods as supply chain-related barriers. Provide a brief explanation of each barrier and its impact on CE adoption in the building industry.
A brief explanation of each barrier and its impact on CE adoption in the building industry has been included 2.1.2 (See lines 251-270).
- Consider discussing the role of regulations and policies as potential barriers to CE adoption in the building industry. This could include challenges related to existing regulations that may not align with CE principles or the need for supportive policies to incentivize sustainable practices.
Challenges related to existing regulations and policies in the construction industry hinder the adoption of CE principles have been included in the manuscript. (See line 574-583).
- Formal methods can be used to verify the correctness of smart contracts and blockchain codes, which can help to prevent costly errors and security breaches. Therefore, it is important to discuss the use of formal methods in your paper. For this purpose, the authors may include the following interesting references (and others):
a. https://ieeexplore.ieee.org/document/9970534
b. https://ieeexplore.ieee.org/document/8328737
The use of formal methods for verification of smart contracts has been included in the manuscript (See line 465-469, and 586-589).
Reviewer 2 Report
Comments and Suggestions for AuthorsThe purpose of this study is to develop a theoretical framework of a digital platform ecosystem for implementing dynamic circular economy within building industry through integration of blockchain technology and multi-criteria decision making approach built upon their synergy.
However, I have some major remarks as follows.
The title is quite long. Suggest to revise the title to be short and precise.
The main findings should be presented in the abstract. The novelty and main findings (quantitative result) should be highlighted in the abstract.
A new section “Literature Review” should be included to discuss the past studies. Then, a table which shows the state of the art should be provided to show the research gap clearly.
In the introduction and methodology, AHP should be mentioned and explained. Figure 1 should be revised to include AHP instead of MCDM approach which is very general.
The methodology of AHP should be presented and explained in details.
In Table 2, there are only three criteria involved in this study. Furthermore, only two alternatives are selected in this study. What is the justification?
Besides, there is only one respondent involved in this study, which is not justifiable. The number of respondents (experts) should be increased in this study. The requirements of respondents should also be specified.
Table 3 is incomplete. The intermediate values such as 2,4,6,8 should also be included.
Comments on the Quality of English LanguageModerate editing of English language required
Author Response
1) The title (Theoretical framework for implementing dynamic circular economy within building industry through integration of blockchain technology and multi-criteria decision making approach) has been shortened using main and subheading as below:
Framework for dynamic circular economy within building industry:
Integration of blockchain technology and multi-criteria decision making approach
2) The novelty as application of BCT and MCDM has already been declared as the text in green below. As the quantitative result the text in red has been added to the abstract, see below:
Abstract has been revised. Main findings and novelty have been included.
Literature review is already included in the section 2. Research gap has already been presented in the introduction. Research gap has been improved in introduction.
MCDM approach including AHP method has been mentioned and explained in the section introduction. The text below has been moved from section 2.1.4 to the introduction.
There exist several methods based on MCDM approach such as Simple Additive Weighting (SAW), Analytic Hierarchy Process (AHP), Analytic Network Process (ANP), TOPSIS, PROMETHEE, DEMATEL, COPRAS, and VIKOR that are commonly used to support the selection of optimal alternatives in engineering projects [73](dos Santos Gonçalves and Campos 2022).
Figure 1 has been revised and include AHP instead of MCDM.
MCDM approach including AHP method has been mentioned and explained in the section introduction.
The least number of criteria and alternatives are two at AHP method. The case study describes a simple example with few data showing the application of AHP method.
We have used the judgement of experts (hypothetical buyers) in the case study to set the weighting of the criteria.
Table 3 is already complete. The numbers are fixed and should not be changed to other values in AHP method.
Reviewer 3 Report
Comments and Suggestions for AuthorsThis article explores innovation by integrating blockchain technology and a multi-criteria decision-making approach to implement a circular economy in the construction industry. This approach is an innovative solution to increase sustainability in the industry.
This article promotes approaches that can increase sustainability in the construction industry, positively impacting the environment and society.
A limitation of this study is that it may focus more on the theoretical framework rather than practical implementation. Integrating blockchain technology and a multi-criteria approach in the construction industry can pose significant technical and organizational challenges that this article may not fully address.
Criticism of the description of this article is as follows.
This description tends to provide general statements about the construction industry's circular economy (CE) concept without providing more specific details or concrete examples. This makes it difficult for the reader to understand how this concept can be practically implemented.
Although it is explained that implementing a decision support system can reduce waste and environmental impact, there is no detailed explanation of how the system can provide real benefits in the context of the construction industry.
We suggest providing concrete examples of projects or initiatives that have successfully adopted the CE concept in the construction industry, supporting these statements with appropriate references, and discussing more specific strategies or solutions to address the identified barriers.
Author Response
A concrete example of project that has successfully adopted the CE concept in the construction industry has been added.
Reviewer 4 Report
Comments and Suggestions for AuthorsThis article introduced the concept of circular economy to the construction industry, and it is novel to integrate blockchain technology with construction informatisation to meet the needs of circular economy. The authors have done rich literature combing, and this paper has theoretical contributions to the sustainable development of the construction industry. However, there are still the following areas for improvement:
1. The title of the article is somewhat complex and lengthy and could be made more concise and attractive.
2. the "Description" column in Table 2 could summarise the highlights of the research in each article rather than just a list of titles.
Comments on the Quality of English LanguageMinor editing of English language required
Author Response
The title (Theoretical framework for implementing dynamic circular economy within building industry through integration of blockchain technology and multi-criteria decision making approach) has been shortened by using main and subheading as below:
Framework for dynamic circular economy within building industry:
Integration of blockchain technology and multi-criteria decision making approach
Answer to comment 2.
Table 1 (not Table 2) has been revised accordingly.
Reviewer 5 Report
Comments and Suggestions for AuthorsEnd of Waste criteria (EoW) and technical valuation of the used built-in materials should be taken into account as well. In line 28 you refer to "overall properties". Are EoW criteria and technical valuation are included? How the development of the digital platform for implementing dynamic CE within building sector is affected?
More detailed comments - Given that the building industry is one of the most resource-intensive sectors, a shift from linear to a circular economy model is necessary. The present research study deals with challenges such as the management of information regarding used/built-in materials and products, the lack of cross-sector documentation tools, and the sales operations for implementing circular economy in the building industry. The purpose is to develop a digital platform for implementing circular economy within the building industry through integration of blockchain technology and multi-criteria decision making approach built upon their synergy. -The topic is original aiming to fill the gap mainly between the management of information regarding used/built-in materials and products for the benefit of implementing the circular economy in the building industry. - The special approach in this work has to do with the synergy of blockchain technology for documentation, and tracing of used/built-in materials and products and multi-criteria decision making approach for ranking and selection of optimal used/built-in materials and products. - End of Waste criteria (EoW) and technical valuation of the used built-in materials should be taken into account as well. In line 28 you refer to "overall properties". Are EoW criteria and technical valuation are included? How the development of the digital platform for implementing dynamic CE within building sector is affected? - The conclusions are consistent with the arguments presented and they address the main question posed. - The references are appropriate - No additional comments on the tables and figures
Comments on the Quality of English Language
Small errors (e.g. line 254) should be traced and corrected
Author Response
We have only considered functionality, product information data and cost as the most important criteria in the case study at section 3.3. Of course, it is possible to include both end of waste and detailed technical valuation criteria of the used/built-in materials and products. To some extent the technical valuation criteria has been measured by the functionality criteria in our study.
Certainly, adding more criteria will enhance ranking and selection of the most sustainable used/built-in materials and products.
Round 2
Reviewer 1 Report
Comments and Suggestions for AuthorsThe authors considered my comments and suggestions.
Comments on the Quality of English LanguageCan be improved.
Author Response
- The quality of English language has been improved.
Reviewer 2 Report
Comments and Suggestions for AuthorsMost of the comments have been addressed in the revised manuscript except the following comments:
1) In Table 2, there are only three criteria involved in this study. Furthermore, only two alternatives are selected in this study. Overall, it is a preliminary study.
2) Besides, there is only one respondent involved in this study, which is not justifiable. The number of respondents (experts) should be increased in this study.
3) Table 3 is incomplete actually. The intermediate values such as 2,4,6,8 should also be included.
Overall, it is a preliminary study with only three criteria, two alternatives and one respondent.
Comments on the Quality of English Language
Minor editing of English language required
Author Response
- We have only considered functionality, product information data and cost as the most important criteria in the case study at section 3.3 as a preliminary study. Certainly it is possible to include several criteria such as end of waste and detailed technical evaluation criteria. Certainly, adding more criteria in a detailed study in the future will enhance ranking and selection of the most sustainable used materials and products.
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The idea with the digital market is that the industry players as buyers and sellers can meet and collaborate on used materials and products during the construction and demolition projects.
The scenario in the case study is that a project leader for a construction project is looking for used freezers at the digital market as hypothetical buyer. He/she enters the digital market and finds two different interesting alternatives. The digital market offers a MCDM approach to ease ranking and selection of alternatives based on the judgement of the project leader.
The text above has been added to the manuscript in page 11, lines 388-390 and page 12 lines 422-426 in red.
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Definitions of fixed nine-degree fundamental weighting scales to compare the criteria have been established by Saaty (1980) where each number has specific definition as follow:
Extremely less important 1/9
Very strongly less important 1/7
Strongly less important 1/5
Moderately less important 1/3
Equal importance 1
Moderately more important 3
Strongly more important 5
Very strongly more important 7
Extremely more important 9
There is no need to include other numbers. - The quality of English language has been improved.
Round 3
Reviewer 2 Report
Comments and Suggestions for AuthorsOverall, it is a preliminary study with only three criteria, two alternatives and one respondent. Besides, Table 3 is incomplete actually. The intermediate values such as 2,4,6,8 must be included as presented in many journals, for example, Evelyn & Yeboah (2015). Ranking agricultural supply chain risk in Ghana: An AHP approach. International Journal of Economics, Commerce and Management, 3(2), 1-12.
Author Response
As a preliminary study we have considered functionality, product information data and cost as the most important criteria. In further study it is possible to include several criteria to enhance selection of the most sustainable used materials and products.
Table 2 has been revised according to the reference Evelyn & Yeboah (2015).
