An Assessment of Lean Design Management Practices in Construction Projects
Round 1
Reviewer 1 Report
This is an interesting study that looks into the compatibility between design management practices and lean construction principles. The study used a variety of research methods for collecting and analysing data and the findings are clearly presented. The study however includes a number of significant limitations and weaknesses that need to be acknowledged and addressed, to allow the study to be published. Suggestions for improvement, include:
1- Providing a rationale to all matters related to the choice of research methods and approaches. For example:
The authors refer to the use of a systematic review, but it has not been explained in the study what criteria for inclusion and exclusion of papers were used, and have led to a final review of 33 papers only. Criteria used for choosing the sample of experts used for evaluation, the 64 projects and the professionals interviewed from each project Why has the study chosen to follow the work adopted by Herrera et al. only and not other studies as well? Why has the study adopted the affinity methods for grouping findings of literature review? Why this method in particular? why did the project management questionnaire developed in this study follow Bloom and Van Reenen's method and not others? what are the weaknesses of a research method which relies on participants own opinions and judgements?
In general, the study reports on what has been done but does not explain why they have been done in such a way. These points raised above need to be addressed, in order to enhance the rigour and credibility of the study.
2- Grammatical mistakes and editing of the paper
The paper needs significant editing to qualify for publication. Some examples include:
Lines 27-29 (last paragraph in abstract) - grammar Lines 42-44 - grammar line 196 LPS is an abbreviation which has not been explained before within the text? Last Planner System (LPS) Line 332 Line 350 The use of bulletin points is encouraged, as it can help to enhance the readability of the paper, especially when reporting on findings. Title of Table 2 needs correction. It's not a characterisation of their answers' it's their profiles, I think?
3- Reliability and accuracy of some of the findings
On page 11, lines 282-284, it is mentioned in the study that the practices that contributed to fewer principles were:
making of decisions at the last responsible moment - This is one of the core principles of Set-based Design, which is one of the most distinguished Lean Design methods PDCA - one of the core principles of LC Multi-criteria decision making - aligns with value engineering and Lean design methods such as Choosing by advantages?
The authors need to explain why these findings seem to lack accuracy and logic. Is this influences by the subjective opinion or experiences of the experts involved in this study? Can choosing different experts lead to different findings.
4- The title needs to be amended to define the scope of the study. So to include for example: An opinion-based survey
5- The study needs to include a separate limitations section and reflect on the limitations of the study, to enable future studies to learn from it. For example:
The study follows a quantitative approach. Could a qualitative study be useful and why? Is it sufficient that two researchers listen to only one interview conducted in each project and come up with validations of the level of of conformance of the used design management practices with LC principles? A standard deviation of 1.48 is still high and could indicate that the descriptions were not clear enough or significant differences in the participants' opinions or experiences or all of these. Is the sample used in the study comprehensive and can the results be generalised? what will the authors do differently if they were to do this study once again does a practice that (fully or partially) aligns with more than once principle be considered more useful or effective than a one that fully aligns with only one principle should the focus be on measuring impact on design management practices on project performance and how this links to LC principles and objectives?
6- Implications:
The study needs to explicitly mention the contributions of this study to theory and practice? Who can benefit from reading this paper and how can it help them?
Author Response
REPLY TO REVIEWERS AND GUIDE TO THE REVISION OF THE PAPER
Journal: SUSTAINABILITY
Title: An Assessment of Lean Design Management Practices in Construction Projects
Manuscript ID: 642480
REVIEWER #1
3.0. This is an interesting study that looks into the compatibility between design management practices and lean construction principles. The study used a variety of research methods for collecting and analysing data and the findings are clearly presented. The study however includes a number of significant limitations and weaknesses that need to be acknowledged and addressed, to allow the study to be published. Suggestions for improvement, include:
The authors wish to thank Reviewer #1 for his/her time and effort in reviewing our manuscript, as well as for his/her suggestions and observations. We have performed a more detailed copyediting. The following is a point-by-point response with a description of what has been changed in the manuscript and our reasoning for the modifications and improvements. We believe that these changes have improved the paper.
3.1. Providing a rationale to all matters related to the choice of research methods and approaches.
In general, the study reports on what has been done but does not explain why they have been done in such a way. These points raised above need to be addressed, in order to enhance the rigour and credibility of the study.
For example: The authors refer to the use of a systematic review, but it has not been explained in the study what criteria for inclusion and exclusion of papers were used, and have led to a final review of 33 papers only.
The authors thank Reviewer #3 for his/her comment. Therefore, we have addressed each of these questions in the best possible way. First, we have added the inclusion and exclusion rules, as explained in the first paragraph of sub-section 2.1 within the Research Method section (Lines 106 to 115):
“A literature review was carried out of specialized journals on engineering and construction project management and of proceedings of main conferences between 1998 and 2018; the search was carried out in the following libraries: Engineering Village, Web of Science and Scopus. The search topics were lean design, design management, lean management, design team, design projects, and LPS® in design. Articles were selected applying three inclusion/exclusion criteria regarding the document: (1) focused on lean; (2) focused on design phase; and (3) reporting lean management practices in a case study. For control and information collection, a table was prepared using Microsoft Excel software; for each document, it comprised information related to title, authors, database, publication year and inclusion/exclusion criteria. In this review, 33 references of implementation or potential implementation of lean design management practices were found.”
3.2. Criteria used for choosing the sample of experts used for evaluation
Following the Reviewer’s suggestion, we have added the criteria used for choosing the sample of experts in the text (Lines 130 to 137):
“The validation was performed based on the judgment of experts (academics and practitioners). The sample was selected from the research network of the Centre of Excellence of Production (GEPUC), complying with the following two requirements: (a) more than 10 years of practice, and (b) experience implementing or researching in lean management and design management. This way, twenty-five experts were invited to take part in this research; out of these twenty-five, fifteen experts agreed to participate (Table 2). The international experts completed a matrix whose columns contained the eleven lean principles and whose rows contained the lean design management practices obtained from the literature review.”
3.3. Criteria used for choosing the sample the 64 projects and the professionals interviewed from each project.
Considering the Reviewer’s suggestion, we have described how we selected the 64 projects in sub-section 2.3 within the Research Method section (Lines 160 to 167):
“To assess the level of implementation of the lean design management practices, the researcher applied the questionnaire in 64 construction projects. The researchers invited to join all the companies who participate in its network of collaborating organizations, of which 64 projects of companies interested were assessed. All projects had a Design-Bid-Build contracting system, so the design was in a contract prior to the construction. Additionally, the projects were divided between building and infrastructure projects and by the design's country of origin; the projects were from Colombia, Chile and Spain (Table 4). Given these classifications, hypothesis tests were carried out to check if there were significant differences by type of classification (country and type of project).”
We have also summarized this information in the Conclusions section (Lines 428 to 430):
“The 64 projects evaluated are not a statistical sample, considering the number of projects in the design process in the countries where they were evaluated; hence a larger number of projects should be assessed”.
3.4. Why has the study chosen to follow the work adopted by Herrera et al. only and not other studies as well?
The study follows the principles proposed originally by the seminal work of Koskela in 1992; this is indicated in our citation (reference 26). Furthermore, we highlighted that those principles were already implemented and adapted by Herrera et al. (2019). In order to consider the Reviewer’s suggestion, we have modified this paragraph in (Lines 123 to 128):
“To validate the previously identified lean design management practices, the researchers assessed the relationship between these practices and the originals lean construction principles proposed by Koskela [26], and adapted by Herrera et al. [27] (Table 1). While these 11 principles were the first to be proposed [26], new principles have been developed [25]. However, all elements are taken up in the original eleven [26], since the new principles [25] are particular to the construction execution.”
3.5. Why has the study adopted the affinity methods for grouping findings of literature review? Why this method in particular?
In order to consider the Reviewer’s suggestion, we have modified the paragraphs in (Lines 188 to 196):
“Affinity methods are used in Design Thinking to help in making sense of the information when data comes from diverse sources/contexts, such as facts, ethnographic research, brainstorming results, users´ opinions and needs, insights, and design issues [29]. Considering the exploratory nature of this study and the mixed nature of the data collected, affinity methods were selected for information classification. From the literature review, 19 lean design management practices were identified and grouped into three categories, using the affinity method [30,31]: stakeholder management, project planning and control, and problem solving and decision making. Below, the practices of each of the categories are presented; for each one of the practices, its supporting references are presented by category.”
3.6. Why did the project management questionnaire developed in this study follow Bloom and Van Reenen's method and not others?
In order to consider the Reviewer’s suggestion, we have modified the paragraphs in (Lines 315 to 321):
“Bloom and Van Reenen's [65] developed a method to measure and explain management practices across firms and countries, which uses open-ended questions. This approach fits better to the current research than absolute scoring grids, and it is a proven model, which is highly cited in the literature. Based on the list of lean design management practices, a project management questionnaire was created that contained five levels [65]. For each practice, the collaborative team of experts (Table 3) proposed a description for scores 1, 3 and 5, while scores 2 and 4 were defined as an intermediate point between 1-3 and 3-5, respectively.”
3.7. What are the weaknesses of a research method which relies on participants own opinions and judgements?
We understand the Reviewer’s concerns. In order to consider the limitations of this research method (common to similar methods based on interviews and focus groups), we have added a new paragraph, stating the limitations at the Conclusions section, as follows (Lines 431 to 438):
“Additionally, this study proposes a quantitative measure of the level of the lean design management practices in each project based on an interview with the project coordinator; this assessment may have a biased view. Therefore, as future work, it could be interesting to conduct an in-depth study of each project that involves the viewpoint of different actors carrying out a qualitative and quantitative assessment of the project. The qualification of each project has to be done with at least two researchers or specialized consultants to provide higher objectivity of the assessment; therefore, future studies could create a tool that would be used as self-evaluation for each project.”
3.8. Grammatical mistakes and editing of the paper:
Lines 27-29 (last paragraph in abstract) - grammar Lines 42-44 - grammar line 196 LPS is an abbreviation which has not been explained before within the text? Last Planner System (LPS) Line 332 Line 350 The use of bulletin points is encouraged, as it can help to enhance the readability of the paper, especially when reporting on findings. Title of Table 2 needs correction. It's not a characterisation of their answers' it's their profiles, I think?
The authors thank Reviewer #3 for his/her comments. We re-wrote the required sentences and paragraphs, as follows:
Lines 27-30 (last paragraph in abstract)
Original text: “This research allows assessing management practices in the design phase of construction projects; then, identify implementations gaps, benchmark with other projects, and improve the design process of this type of projects, though a taxonomy of lean design management practices.”
Proposed text: “This research proposes a tool to assess management practices in the design phase of construction projects; then, the study identifies implementations gaps, it provides benchmarks with other projects, and it improves the design process through a taxonomy of lean design management practices.”
Lines 42-45 (grammar)
Original text: “Although there is no tradition of integral management of the design process, in recent years options have been studied to evaluate its performance [7], implemented integrated management systems, visual management tools [8] and powerful technological tools to optimize this process [6]”
Proposed text: “Although there is no tradition of integral management of the design process, in recent years, several options have been studied: to evaluate its performance [7], to implement integrated management systems and visual management tools [8], as well as to optimize this process [6]”
Lines 42-44 LPS is an abbreviation which has not been explained before within the text? Last Planner System (LPS) Line 332
In lines 54-55 we have defined for first time the LPS abbreviation.
Text: “last planner® system (LPS®)”
Line 350 The use of bulletin points is encouraged, as it can help to enhance the readability of the paper, especially when reporting on findings
We appreciate the Reviewer’s suggestion. However, in this case, we think that the text is better as it is.
Title of Table 2 needs correction. It's not a characterisation of their answers' it's their profiles, I think?
We have changed the title of Table 2:
Original text: “Table 2. Characterization of the expert’s answers”
Proposed text: “Table 2. Characterization of the experts who answered the matrix”
3.9. Reliability and accuracy of some of the findings. On page 11, lines 282-284, it is mentioned in the study that the practices that contributed to fewer principles were:
making of decisions at the last responsible moment - This is one of the core principles of Set-based Design, which is one of the most distinguished Lean Design methods PDCA - one of the core principles of LC Multi-criteria decision making - aligns with value engineering and Lean design methods such as Choosing by advantages?
The authors need to explain why these findings seem to lack accuracy and logic. Is this influences by the subjective opinion or experiences of the experts involved in this study? Can choosing different experts lead to different findings.
The authors appreciate the reviewer's comments, as they convey a very valid and important interpretation of our results. In this regard, we recognize that the results are subject to the knowledge, experience, assumptions, and personal views of the experts, which is intrinsic to this research method. On the other hand, the reviewer´s comments made us realize that we might be giving a wrong idea about the importance of these management practices. They are linked to 3-5 (out of the 11 principles of lean construction) so their ratio is not low, but it is relatively smaller than the other management practices. However, this does not mean that these practices are less important.
We included the above arguments/discussion in the paragraph below (Lines 300 to 307).
“The practices that contributed to fewer principles were the making of decisions at the last responsible moment, plan-do-check-act (PDCA) problem solving, multicriteria decision making, and benchmarking to obtain information for planning. Three of these four practices corresponded to the problem solving and decision-making category; therefore, there would be a knowledge gap associated with the approach of this type of implementation of the lean construction principles. It is important to mention that the number of lean construction principles related to a practice does not imply that this practice is more or less important in the process of implementing lean to the design process.”
3.10. The title needs to be amended to define the scope of the study. So to include for example: An opinion-based survey
The authors thank Reviewer #1 for his/her comment. Anyway, we prefer to keep the title as it is. However, we have added this idea concerning the expert survey and the questionnaire in the Abstract (Lines 19 to 21):
“…a validation of lean design management practices with a practice-principle relationship, based on an expert survey; the devolvement of a tool (questionnaire) to evaluate the lean design management practices…”
3.11. The study needs to include a separate limitations section and reflect on the limitations of the study, to enable future studies to learn from it. For example:
The study follows a quantitative approach. Could a qualitative study be useful and why? Is it sufficient that two researchers listen to only one interview conducted in each project and come up with validations of the level of of conformance of the used design management practices with LC principles? A standard deviation of 1.48 is still high and could indicate that the descriptions were not clear enough or significant differences in the participants' opinions or experiences or all of these. Is the sample used in the study comprehensive and can the results be generalised? what will the authors do differently if they were to do this study once again does a practice that (fully or partially) aligns with more than once principle be considered more useful or effective than a one that fully aligns with only one principle should the focus be on measuring impact on design management practices on project performance and how this links to LC principles and objectives?
We appreciate the Reviewer’s suggestion. While we are not including a separate section from the Conclusions section about limitations and future studies, we are adding both elements separately in the last paragraph of the Conclusion section, in the following way (Lines 426 to 447):
“Some limitations of this research are state next. The identified practices were not necessarily the only ones since the practices associated with information technology were not considered, such as the use of BIM or the cloud. The 64 projects evaluated are not a statistical sample considering the number of projects in the design process in the countries where they were evaluated, hence a larger number of projects should be assessed. Also, the authors did not assess specific tools, such as, last planner system, target value design or others. Additionally, this study proposes a quantitative measure of the level of the lean design management practices in each project based on an interview with the project coordinator; this assessment may have a biased view. Therefore, as future work, it could be interesting to conduct an in-depth study of each project that involves the viewpoint of different actors carrying out a qualitative and quantitative assessment of the project. The qualification of each project has to be done with at least two researchers or specialized consultants to provide higher objectivity of the assessment; therefore, future studies could create a tool that would be used as self-evaluation for each project. In addition, this study did not measure the effect of the application of the lean design management practices on the performance of the 64 projects. Therefore, future research should aim to assess the performance of the design process and the organizational performance of the design team; in this way it will be possible to identify the effect of lean design management practices on the performance of the construction project, both during its design and in its execution. Future research should also consider practices associated with information technology, specifically, the collaborative work in the cloud and the use of BIM, to evaluate a larger number of projects of different types to understand and identify the gaps and opportunities for improvement that exist in the design phase of construction projects and understand the impacts of these practices on the performance of projects.”
3.12. Implications:
The study needs to explicitly mention the contributions of this study to theory and practice? Who can benefit from reading this paper and how can it help them?
We appreciate the Reviewer’s suggestion. We have improved the Conclusions, adding several additional sentences in the first paragraph, and dividing this one into two different paragraphs. The first has the theoretical contribution and the second has the practical contribution (Lines 395 to 425):
“In this study, evidence was encountered in the literature about the implementation or potential implementation of at least 19 practices of the lean philosophy in the design process of construction projects. These practices were framed in three main areas: stakeholder management, planning and control, and problem solving and decision making. Each of the 19 practices had a high degree of relation with lean construction principles and revealed a balanced contribution to each of the principles of the lean philosophy; therefore, the defined practices could be regarded as lean practices in the design of construction projects. Some principles were most used during the design phase: increasing the output value through systematic consideration of customer requirements, reducing the amount of nonvalue adding activities, reducing the process variability, reducing the cycle times, increasing the process transparency, and continuously improving processes. On the other hand, the principles that were least used were: increasing the output flexibility, balancing the flow improvement with conversion improvement and benchmarking. The practices that contributed to a larger number of principles were: simultaneous design of the product and construction process, use of benchmarking information to make decisions, definition of activities, milestones and control points, and collaborative planning. The lean design management practices that contributed to fewer principles were: making of decisions at the last responsible moment, plan-do-check-act (PDCA) problem solving, multi-criteria decision making, and benchmarking to obtain information for planning.”
“Furthermore, this research proposed a tool (questionnaire) to evaluate the degree of implementation of each of the practices at the project level, defining a taxonomy of lean design management practices. The tool consisted of two researchers individually qualifying project practices based on interviews with project managers and then making collaborative decisions. This way, the authors carried out an evaluation of the 19 lean design management practices to 64 construction projects at the design phase where a high variability in the levels of lean implementations could be observed. The most developed practices are: requirement management and active participation of the client; the least developed are: builders in early stages, decision-making until the last responsible moment, and multi-criteria decision-making. Therefore, there is a great opportunity to implement these practices in the design process and to continuously improve the implementation of lean design practices that are at the initial levels of development. Construction executives, project managers and designers can benefit from this tool as it helps them to identify the main development gaps in the best practices of design management. Additionally, they can use the data obtained in this study to benchmark their lean design management practice.”
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Dear Authors,
I found your research vary interesting, significant and methodical. I have only comments and some suggestions, which are listed below:
1) Introduction
Please consider if you would like to mention IPD approach since it can contribute to lean design management practices. When you mention about several lean tools, I think it would be worth to mention lean and BIM matrix, elaborated by Sacks et al. (2010) - your ref. no. 26.
2) Generic suggestions
- In my opinion, it would be more coherent to use one nomenclature - lean design management practices. Sometimes you call them lean design management, design management or design management practices as lean focused.
- The full name of LPS is Last Planner® System and abbreviation LPS. Sometimes you use LPS or LPS®
- Line 244 - The aformentioned was expected... I think the subject is missing
- Line 337 - Spearman's Rho coefficient
3) Please consider to highlight the key findings of your research (relationship between design management practices and lean principles as well as assessment in 3.3).
Author Response
REPLY TO REVIEWERS AND GUIDE TO THE REVISION OF THE PAPER
Journal: SUSTAINABILITY
Title: An Assessment of Lean Design Management Practices in Construction Projects
Manuscript ID: 642480
REVIEWER #1
1.0. I found your research vary interesting, significant and methodical. I have only comments and some suggestions, which are listed below:
The authors wish to thank Reviewer #1 for his/her time and effort in reviewing our manuscript, as well as for his/her suggestions and observations. We have performed a more detailed copyediting. The following is a point-by-point response with a description of what has been changed in the manuscript and our reasoning for the modifications and improvements. We believe that these changes have improved the paper.
1.1. Introduction: Please consider if you would like to mention IPD approach since it can contribute to lean design management practices
We agree with the Reviewer that we have to include the IPD in the Introduction. We added a paragraph between Lines 59 to 63:
“Additionally, the Integrated Project Delivery (IPD) has emerged as a new project delivery system with the potential to provide more collaboration and better performance through more supply chain integration, where the owner, designer and constructor sign a single multiparty contract and they build a common culture in the organization that encourages team collaboration [19]”
1.2. Introduction: When you mention about several lean tools, I think it would be worth to mention lean and BIM matrix, elaborated by Sacks et al. (2010) - your ref. no. 26.
The authors thank Reviewer #1 for his/her comment. We added the lean and BIM matrix when we mentioned several lean tools (in Lines 73 to 76):
“In the BIM case, Sacks, Koskela, Dave and Owen [24] propose a matrix that links Lean Construction principles with BIM functionalities; they identify 56 issues that are presented as hypotheses being intended to guide and stimulate further research.”
1.3. In my opinion, it would be more coherent to use one nomenclature - lean design management practices. Sometimes you call them lean design management, design management or design management practices as lean focused.
The authors are grateful for Reviewer #1's observations regarding this matter, which improves the homogeneity and understanding of the text as well as the reading flow. Therefore, we have performed the following changes:
Lines 86, 104, 109, 111, 127, 130, 136, 180, 181, 226, 227, 247, 262, 263, 264 and 282: We have changed “design management practices” for “lean design management practices”. Line 117: We have changed “lean practices” for “lean design management practices”. Line 118: We have changed “design management practices as lean focused” for “lean design management practices”. Lines 15, 19, 40, 52, and 108: When referring to “design management”, we have not made the change, because in this case we refer to design management in general and not specifically to lean design management practices.
1.4. The full name of LPS is Last Planner® System and abbreviation LPS. Sometimes you use LPS or LPS®
The authors thank Reviewer #1 for his/her comment. We changed all the acronyms LPS to LPS®.
1.5. Line 244 - The aformentioned was expected... I think the subject is missing
We agree with the Reviewer, so we rewrote the sentence (Line 252) in this way:
“This was a predictable result, since during the design phase, clients are provided with a first approximation of the final product that they expect to receive.”
1.6. Line 337 - Spearman's Rho coefficient
We thank the Reviewer for this suggestion. Therefore, we changed the rho coefficient by “Spearman's Rho coefficient” in Line 346.
1.7. Conclusion: Please consider to highlight the key findings of your research (relationship between design management practices and lean principles as well as assessment in 3.3).
We appreciate the Reviewer’s suggestion. We have improved the Conclusions, adding several additional sentences in the first paragraph, and dividing this one into two different paragraphs, in the following way:
“In this study, evidence was encountered in the literature about the implementation or potential implementation of at least 19 practices of the lean philosophy in the design process of construction projects. These practices were framed in three main areas: stakeholder management, planning and control, and problem solving and decision making. Each of the 19 practices had a high degree of relation with lean construction principles and revealed a balanced contribution to each of the principles of the lean philosophy; therefore, the defined practices could be regarded as lean practices in the design of construction projects. Some principles were most used during the design phase: increasing the output value through systematic consideration of customer requirements, reducing the amount of nonvalue adding activities, reducing the process variability, reducing the cycle times, increasing the process transparency, and continuously improving processes. On the other hand, the principles that were least used were: increasing the output flexibility, balancing the flow improvement with conversion improvement and benchmarking. The practices that contributed to a larger number of principles were: simultaneous design of the product and construction process, use of benchmarking information to make decisions, definition of activities, milestones and control points, and collaborative planning. The lean design management practices that contributed to fewer principles were: making of decisions at the last responsible moment, plan-do-check-act (PDCA) problem solving, multi-criteria decision making, and benchmarking to obtain information for planning.”
“Furthermore, this research proposed a tool (questionnaire) to evaluate the degree of implementation of each of the practices at the project level, defining a taxonomy of lean design management practices. The tool consisted of two researchers individually qualifying project practices based on interviews with project managers and then making collaborative decisions. This way, the authors carried out an evaluation of the 19 lean design management practices to 64 construction projects at the design phase where a high variability in the levels of lean implementations could be observed. The most developed practices are: requirement management and active participation of the client; the least developed are: builders in early stages, decision-making until the last responsible moment, and multi-criteria decision-making. Therefore, there is a great opportunity to implement these practices in the design process and to continuously improve the implementation of lean design practices that are at the initial levels of development.”
“Some limitations of this research are the following: the identified practices were not necessarily the only ones since the practices associated with information technology were not considered, such as the use of BIM or the cloud. Also, the authors did not assess specific tools, such as, last planner system, target value design or others. In addition, this study did not measure the effect of the application of the lean design management practices on the performance of the 64 projects. Therefore, future research should aim to assessing the performance of the design process and the organizational performance of the design team; in this way it will be possible to identify the effect of lean design management practices on the performance of the construction project, both during its design and in its execution. Future research should also consider practices associated with information technology, specifically, the collaborative work in the cloud and the use of BIM, to evaluate a larger number of projects of different types to understand and identify the gaps and opportunities for improvement that exist in the design phase of construction projects and understand the impacts of these practices on the performance of projects.”
The authors appreciate the remarks made by Reviewer #1 and believe his/her suggestions and observations have greatly improved the manuscript.
Author Response File: 
Author Response.docx
Reviewer 3 Report
Lean management is widely used in the construction projects, therefore the subject is interesting and challenging. Congratulations to authors!
In my opinion, some elements should be added to the research:
Row 98-103: is there a reason for choosing only conferences, and not also articles in journals concerning lean management in constructions?
Is there evidence of effects in applying lean management principles on the 64 projects investigated by the authors? Can you provide examples (good or bad)?
Which were the reasons for selecting the projects: are they similar in terms of size, location, resources? Otherwise you cannot compare them.
The conclusions should be developed for highlighting the importance of lean in constructions.
Author Response
REPLY TO REVIEWERS AND GUIDE TO THE REVISION OF THE PAPER
Journal: SUSTAINABILITY
Title: An Assessment of Lean Design Management Practices in Construction Projects
Manuscript ID: 642480
REVIEWER #2
2.0. Lean management is widely used in the construction projects, therefore the subject is interesting and challenging. Congratulations to authors!
The authors wish to thank Reviewer #2 for his/her time and effort in reviewing our manuscript, as well as for his/her suggestions and observations. We have performed a more detailed copyediting. The following is a point-by-point response with a description of what has been changed in the manuscript and our reasoning for the modifications and improvements. We believe that these changes have improved the paper.
2.1. In my opinion, some elements should be added to the research. Row 98-103: is there a reason for choosing only conferences, and not also articles in journals concerning lean management in constructions?
We appreciate the Reviewer’s advice in this matter. We clarified that the search was carried out in specialized journals and conferences (Line 105-106):
“A literature review was carried out of specialized journals on engineering and construction project management and of proceedings of main conferences between 1998 and 2018.”
2.2. Is there evidence of effects in applying lean management principles on the 64 projects investigated by the authors? Can you provide examples (good or bad)?
The authors appreciate the recommendation to add the effects of the application of lean design management practices on the 64 projects. However, it was not possible to assess the impact of the lean practices as these measurements required resources that were not available for this study.. Therefore, it is highlighted as a limitation, as well as a future research line at the Conclusion section, in the following way (lines 411 to 416):
“…In addition, this study did not measure the effect of the application of the lean design management practices on the performance of the 64 projects. Therefore, future research should aim to assess the performance of the design process and the organizational performance of the design team; in this way it will be possible to identify the effect of lean design management practices on the performance of the construction project, both during its design and in its execution…”
2.3. Which were the reasons for selecting the projects: are they similar in terms of size, location, resources? Otherwise you cannot compare them.
We appreciate the Reviewer’s advice in this matter. We clarified the similar and differentiating elements among the 64 projects in Lines 153 to 159, in the following way:
“The researchers invited to join all the companies who participate in its network of collaborating organizations, of which 64 projects of companies interested were assessed. All projects had a Design-Bid-Build contracting system, so the design was in a contract prior to the construction. Additionally, the projects were divided between building and infrastructure projects and by the design's country of origin; the projects were from Colombia, Chile and Spain (Table 4). Given these classifications, hypothesis tests were carried out to check if there were significant differences by type of classification (country and type of project).”
2.4. The conclusions should be developed for highlighting the importance of lean in constructions.
We appreciate the Reviewer’s suggestion. We have improved the Conclusions, adding several additional sentences in the first paragraph, and dividing this one into two different ones, in the following way:
“In this study, evidence was encountered in the literature about the implementation or potential implementation of at least 19 practices of the lean philosophy in the design process of construction projects. These practices were framed in three main areas: stakeholder management, planning and control, and problem solving and decision making. Each of the 19 practices had a high degree of relation with lean construction principles and revealed a balanced contribution to each of the principles of the lean philosophy; therefore, the defined practices could be regarded as lean practices in the design of construction projects. Some principles were most used during the design phase: increasing the output value through systematic consideration of customer requirements, reducing the amount of nonvalue adding activities, reducing the process variability, reducing the cycle times, increasing the process transparency, and continuously improving processes. On the other hand, the principles that were least used were: increasing the output flexibility, balancing the flow improvement with conversion improvement and benchmarking. The practices that contributed to a larger number of principles were: simultaneous design of the product and construction process, use of benchmarking information to make decisions, definition of activities, milestones and control points, and collaborative planning. The lean design management practices that contributed to fewer principles were: making of decisions at the last responsible moment, plan-do-check-act (PDCA) problem solving, multi-criteria decision making, and benchmarking to obtain information for planning.”
“Furthermore, this research proposed a tool (questionnaire) to evaluate the degree of implementation of each of the practices at the project level, defining a taxonomy of lean design management practices. The tool consisted of two researchers individually qualifying project practices based on interviews with project managers and then making collaborative decisions. This way, the authors carried out an evaluation of the 19 lean design management practices to 64 construction projects at the design phase where a high variability in the levels of lean implementations could be observed. The most developed practices are: requirement management and active participation of the client; the least developed are: builders in early stages, decision-making until the last responsible moment, and multi-criteria decision-making. Therefore, there is a great opportunity to implement these practices in the design process and to continuously improve the implementation of lean design practices that are at the initial levels of development.”
“Some limitations of this research are the following: the identified practices were not necessarily the only ones since the practices associated with information technology were not considered, such as the use of BIM or the cloud. Also, the authors did not assess specific tools, such as, last planner system, target value design or others. In addition, this study did not measure the effect of the application of the lean design management practices on the performance of the 64 projects. Therefore, future research should aim to assess the performance of the design process and the organizational performance of the design team; in this way it will be possible to identify the effect of lean design management practices on the performance of the construction project, both during its design and in its execution. Future research should also consider practices associated with information technology, specifically, the collaborative work in the cloud and the use of BIM, to evaluate a larger number of projects of different types to understand and identify the gaps and opportunities for improvement that exist in the design phase of construction projects and understand the impacts of these practices on the performance of projects.”
The authors appreciate the remarks made by Reviewer #2 and believe his/her suggestions and observations have greatly improved the manuscript.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
Well done. A final proofreading and text editing of the paper, especially parts that have been added when addressing reviewers' comments, would be useful.
