Round 1

Reviewer 1 Report

General comments:

Often, the authors indicate what the paper is intended to show, summarize, evaluate, explain, promote, expand etc.  ... These phrases promise a lot of what the paper must fulfill. And then the results are insufficiently described. Therefore, it is not clear what supports the conclusions.

There could be more references in the introduction.

Section 3:
It is not clear why these 15 IPD principles were proposed. What were the sources or reasons for the choice.

Table 1 must be improved. It is not clear which secondary indexes belong to the specific antecedent variables.

Section 4 must be improved.
It seems that Tables 3, 4, 5, and 6 are the most important findings.
First:
The grouping of the variables in Table 3 is not clear.
The condition variables in Table 5 are confusing.
It is not clear that Table 6 describes the different paths.
Second:
These tables need to be described much better, in much more detail and more precisely!
The text has to explain the tables.
The entire paper is based on these results.

Some references miss the page numbers of the paper.

Style suggestions:

Quite often spaces are missing (e.g., table and figure numbering, before citations in the text).

Sometimes commas are missing.

Please avoid one- or two-sentence-paragraphs.

Section 3.2.3: The named three main ways should be listed in a listing, not in own paragraphs.

Author Response

Dear Reviewer,

Many thanks for your kind work on our manuscript, and we should also express our sincere thanks to your invaluable comments and suggestions which make our manuscript perfect. We have made a thorough revision according to your comments. Our answers are shown as follows:

1. Often, the authors indicate what the paper is intended to show, summarize, evaluate, explain, promote, expand etc.  ... These phrases promise a lot of what the paper must fulfill. And then the results are insufficiently described. Therefore, it is not clear what supports the conclusions..

ANSWER: Done. Thank you for your reminder. We have added 4 paragraphs to describe the different paths in 4 samples as following:

In overall sample, which includes all respondents, there exist 2 configuration paths. Path S1A shows that contractual principles is absent as the core condition, whereas behavioral principles and catalysts for IPD have no impact on low collaboration level. Concerning the path S1B, it indicates that behavioral principles is absent as the core condition, catalysts for IPD exists as the edge condition and contractual principles has no impact on low collaboration level.

In sample 1, which includes the respondents that are inexperienced and unfamiliar with IPD, there exists 1 configuration path. Path 2 shows that contractual principles, behavioral principles and catalysts for IPD are all absent as the core conditions for low collaboration level.

In sample 2, which includes the respondents who are inexperienced though informed about IPD, there exist 2 configuration paths. Path S3A indicates that behavioral principles is absent as the core condition, catalysts for IPD exists as the edge condition, and contractual principles has no impact on low collaboration level. Path S3B shows that contractual principles and catalysts for IPD are absent as the core condition, behavioral principles exists as the edge condition.

In sample 3, which includes the respondents who are experienced with IPD, there exist 2 configuration paths. Path S4A shows that contractual principles is absent as the core condition, behavioral principles exists as the edge condition, and catalysts for IPD has no impact on low collaboration level. Path S4B indicates that behavioral principles is absent as the core condition, catalysts for IPD exists as the edge condition, and contractual principles has no impact on low collaboration level.

Besides, in the discussion part, we also compared more literatures to support our conclusions drawn from the results in the main text.

2. There could be more references in the introduction.

ANSWER: Done. Thank you very much for your kind suggestion! We have supplemented the introduction with 12 references that shed light on us, the references include:

1. Fischer, M., H.W. Ashcraft, D. Reed, and A. Khanzode. Integrating project delivery: John Wiley & Sons 2017, http://dx.doi.org/10.1002/9781119049272.app04 .
2. Gallaher M P , O'Connor A C , Dettbarn J L , et al. Cost Analysis of Inadequate Interoperability in the U.S. Capital Facilities Industry 2004, Retrieved from www.bfrl.nist.gov/oae/ on Jun. 11, 2009.
3. Chang C Y , Pan W , Howard R . Impact of Building Information Modeling Implementation on the Acceptance of Integrated Delivery Systems: Structural Equation Modeling Analysis[J]. Journal of Construction Engineering and Management 2017, 143(8), 04017044.1-04017044.10.
4. Ghassemi, R.; Becerik-Gerber, B. Transitioning to integrated project delivery: Potential barriers and lessons learned. Lean Construction Journal 2011, 2011, 32–52.
5. Durdyev, S.; Hosseini, M.R.; Martek, I.; Ismail, S.; Arashpour, M. Barriers to the use of integrated project delivery (ipd): A quantified model for malaysia. Engineering Construction & Architectural 2019, 27, 186–204.
6. Kelly, D. Investigating the Relationships of Project Performance Measures with the Use of Building Information modeling (BIM) and Integrated Project Delivery (IPD). Ph.D. Thesis, Eastern Michigan University, Ypsilanti, MI, USA, 2015. Available online: https://commons.emich.edu/theses/599/ (accessed on 1 November 2021).
7. Elghaish, F.; Hosseini, M.R.; Talebi, S.; Abrishami, S.; Martek, I.; Kagioglou, M. Factors driving success of cost management practices in integrated project delivery (ipd). Sustainability 2020, 12, 9539.
8. Choi, J.; Yun, S.; Leite, F.; Mulva, S.P. Team integration and owner satisfaction: Comparing integrated project delivery with construction management at risk in health care projects. Journal of Management in Engineering 2019, 35(1), 05018014.
9. Hanna, A.S. Benchmark performance metrics for integrated project delivery. Journal of Construction Engineering and Management -Asce 2016, 142, 04016040.
10. Mei, T.T.;Wang, Q.K.; Xiao, Y.P.; Yang, M. Rent-seeking behavior of bim & ipd-based construction project in china. Engineering Construction & Architectura 2017, 24, 514–536.
11. Xu, Y.Q.; Kong, Y.Y. The research status and forecast of ipd in china. Journal of Engineering Management 2016, 30, 12–17.
12. He, Q.; Wang, G.; Luo, L.; Shi, Q.; Xie, J.; Meng, X. Mapping the managerial areas of building information modeling (bim) using scientometric analysis. International Journal of Project Management 2017, 35, 670–685.

3. Section 3:

3.1 It is not clear why these 15 IPD principles were proposed. What were the sources or reasons for the choice?

ANSWER: Done. Thank you for your reminder. We are very sorry that we did not explain the sources of 15 IPD principles clearly in the article, which has brought you confusion. To solve this problem, we make the following explanation: These 15 IPD principles were proposed based on the reference Integrated project delivery for public and private owners. IPD principles include contractual principles, behavioral principles and catalysts for IPD. This category is derived from the page 6~7 of reference [11].

11. NASFA; COAA; APPA; AHEFO; AGC; AIA, Integrated project delivery for public and private owners. 2010. (pp:6~7)：

3.2 Table 1 must be improved. It is not clear which secondary indexes belong to the specific antecedent variables.

ANSWER: Done. Thank you very much for your kind suggestion! We have clarified the antecedent variable to which the secondary indicators belong by adding the explanations in the first column of table 1 in the following. The secondary indexes of X1~X8 belong to contractual principles, the secondary indexes of X9~X11 belong to behavioral principles, and the secondary indexes of X12~X15 belong to catalysts for IPD.

Table1. Selection of antecedent variables

4. Section 4 must be improved. It seems that Tables 3, 4, 5, and 6 are the most important findings.

4.1 The grouping of the variables in Table 3 is not clear. The condition variables in Table 5 are confusing. It is not clear that Table 6 describes the different paths.

ANSWER: Done. Thank you very much for your question!

About the table 3 (now table 4), we have added a blank row after the end row of every group to clarify the grouping of the variables in Table 3 (now table 4) as the following.

Table 4. Descriptive statistics

About the table 5 (now table 6), we have added a note after the end of table to clarify the confusing variables in Table 5 (now table 6) as the following. ~ represents the absence of the corresponding condition variable. For example, Contractual Principles represents the presence of contractual principles, and ~ Contractual Principles represents the absence of contractual principles.

Table 6. Analysis of antecedents’ necessary condition under multiple samples

Note: A sideways tilde ~ indicates the absence or negation of the causal condition.

About the table 6 (now table 7), we can use another table form which doesn’t show in the main text to express the contents of Table 6 (now table 7), we also have added 4 paragraphs to describe the different paths in 4 samples as following:

Legend: A sideways tilde ~ indicates the absence or negation of the causal condition. An asterisk * indicates conjunctive. ~Contractual Principles indicates that the condition is a core condition, and ~Contractual Principles indicates that the condition is an edge condition.

In overall sample, which includes all respondents, there exist 2 configuration paths. Path S1A shows that contractual principles is absent as the core condition, whereas behavioral principles and catalysts for IPD have no impact on low collaboration level. Concerning the path S1B, it indicates that behavioral principles is absent as the core condition, catalysts for IPD exists as the edge condition, and contractual principles has no impact on low collaboration level.

In sample 1, which includes the respondents that are inexperienced and unfamiliar with IPD, there exists 1 configuration path. Path 2 shows that contractual principles, behavioral principles and catalysts for IPD are all absent as the core conditions for low collaboration level.

In sample 2, which includes the respondents who are inexperienced though informed about IPD, there exist 2 configuration paths. Path S3A indicates that behavioral principles is absent as the core condition, catalysts for IPD exists as the edge condition, and contractual principles has no impact on low collaboration level. Path S3B shows that contractual principles and catalysts for IPD are absent as the core condition, behavioral principles exists as the edge condition.

In sample 3, which includes the respondents who are experienced with IPD, there exist 2 configuration paths. Path S4A shows that contractual principles is absent as the core condition, behavioral principles exists as the edge condition, and catalysts for IPD has no impact on low collaboration level. Path S4B indicates that behavioral principles is absent as the core condition, catalysts for IPD exists as the edge condition, and contractual principles has no impact on low collaboration level.

4.2 These tables need to be described much better, in much more detail and more precisely! The text has to explain the tables. The entire paper is based on these results.

ANSWER: Done. Thank you very much for your kind suggestion!

In the results, we have described table Tables 3, 4, 5, and 6 (now table 4, 5, 6, 7) in more detail and more precisely in the main text.

About Tables 3 (now table 4), we have described as follows:

The background distribution of respondents was analyzed, as shown in Table 4. Respondents were mainly chosen from construction units, design units, and universities and research institutions, and the proportion of every unit is relative balanced and covers a wide range. Moreover, more than two third of the respondents were engaged in the construction industry for more than three years and nearly half of them have participated in more than three BIM projects, respondents with long-term industry experience and sufficient BIM project experience make their responses have reference significance for related research. In addition, nearly 90% of the respondents have a strong desire to use BIM technology. As BIM is the basis for the rapid development of the IPD, the participants working on BIM projects and their strong willingness to use BIM have a strong reference for the analysis of the IPD project collaboration.

About Tables 4 (now table 5), we have added as follows in Line421-425 in 4.1.3:

Respondents that are inexperienced and unfamiliar with IPD accounts for 38.3% of the total, respondents who are inexperienced though informed about IPD accounts for 44.7% of the total and respondents who are experienced with IPD accounts for 17% of total.

About Tables 5 (now table 6), we have rewritten the original paragraph as follows in Line457-474 in 4.2.2 and added a note to explain the table 6:

The necessary conditions of a single factor are obtained, as shown in Table 6. Consistency is similar to the coefficient significance degree (p-value) in regression analysis, which refers to what extent a certain result requires the existence of a certain variable. Coverage refers to the extent to which a subset physically covers the target set, which is a direct indicator of the empirical importance of antecedent conditions. In fact, when the consistency is below 0.9, neither sample has a bottleneck yet there is little collaboration [15, 16]. As can be seen from Table 5, the necessary conditions were absent in both the overall sample and sample 1. Although in samples 2 and 3, the necessary conditions (contractual principles, behavioral principles and catalysts for IPD in sample 2; catalysts for IPD in sample 3) of low collaboration level exist, but the low coverage of necessary conditions less than 0.8 means that these subsets don’t account for a large proportion of the total. Therefore, the multiple antecedent conditions need to be combined for configuration analysis in this study.

About Tables 6 (now table 7), we have added as follows in Line503-532 in 4.2.3 before table 7:

In overall sample, which includes all respondents, there exist 2 configuration paths. Path S1A shows that contractual principles is absent as the core condition, whereas behavioral principles and catalysts for IPD have no impact on low collaboration level. Concerning the path S1B, it indicates that behavioral principles is absent as the core condition, catalysts for IPD exists as the edge condition, and contractual principles has no impact on low collaboration level.

In sample 1, which includes the respondents that are inexperienced and unfamiliar with IPD, there exists 1 configuration path. Path 2 shows that contractual principles, behavioral principles and catalysts for IPD are all absent as the core conditions for low collaboration level.

In sample 2, which includes the respondents who are inexperienced though informed about IPD, there exist 2 configuration paths. Path S3A indicates that behavioral principles is absent as the core condition, catalysts for IPD exists as the edge condition, and contractual principles has no impact on low collaboration level. Path S3B shows that contractual principles and catalysts for IPD are absent as the core condition, behavioral principles exists as the edge condition.

In sample 3, which includes the respondents who are experienced with IPD, there exist 2 configuration paths. Path S4A shows that contractual principles is absent as the core condition, behavioral principles exists as the edge condition, and catalysts for IPD has no impact on low collaboration level. Path S4B indicates that behavioral principles is absent as the core condition, catalysts for IPD exists as the edge condition, and contractual principles has no impact on low collaboration level.

4.3 Some references miss the page numbers of the paper.

ANSWER: Done. Thank you very much for your kind suggestion! We have supplemented the missing page numbers of the related references in the References.

5. Style suggestions: Quite often spaces are missing (e.g., table and figure numbering, before citations in the text).Sometimes commas are missing. Please avoid one- or two-sentence-paragraphs. Section 3.2.3: The named three main ways should be listed in a listing, not in own paragraphs.

ANSWER: Done. Thank you very much for your kind suggestion! We have added missing spaces and commas in the whole text. As for the one- or two-sentence-paragraphs, we have merged paragraphs appropriately. In Section 3.2.3: The named three main ways have been listed in a table 3 as shown in following.

Table 3. Three main ways to distribute the questionnaire

Author Response File: Author Response.pdf

Reviewer 2 Report

This study aims to increase the effectiveness of collaborative management of construction projects by encouraging the application of IPD principles. The work is in the scope of the journal, however, redaction and structure should be improved as indicated below, especially the methods should be clearer; the author is recommended to identify and practice sophisticated objectives for a journal publication. The author must justify the following points:

Comment 1: It was impossible for me to identify the novelty of the paper. Please state the novelty of this paper in answer to the comments: Do we have existing studies on an exactly similar topic? What is the specific contribution relevant to existing similar studies? Please provide some references related to similar existing studies and then the authors could state the contribution clearly in the manuscript. Hence, the paper should be revised to highlight novelties. Please consider that this lack of novelty starts with the Abstract, Introduction, and Conclusion.

Comment 2: In the Introduction section, there is a lack of references for the several pieces of information that the author presented. For example, this part of the study says, “With the increase in technical complexity and the diversification of specifications of these construction projects, the delivery is becoming increasingly fragmented.” Is it a result developed by the author or cited from other works? Please insight and check for the whole manuscript.

Comment 3: A deep analysis of recent scientific papers covering only the topic and leading to the submission hypothesis based on the gap analysis of the previously published research is required. This step is necessary to cover all the applied methodologies in the proposed methods of this study.

Comment 4: I would suggest adding the questionnaire survey as a supplementary file in order to facilitate the understanding of issues for the readers.   

Comment 5: The proposed approach in section (3) is not outlined with the necessary vigor. The author needs to include sufficient methodological details in the paper and elaborate on the produced results from the proposed methods. Some sections must be added and others need to be relocated and rewritten to make it clearer for the readers. Besides, Figure 3 must be explained and justified better in the text.

Comment 6: The Discussion section should be improved by including a clear and concise analysis of all results presented in the previous section rather than comparing them with the results of previous research. It might be helpful to use more figures to present the results.

Comment 7: Please try to avoid using the numerical way in presenting the results in the Conclusion section.  

Comment 8: Proofreading by a native English speaker should be conducted to improve clarity and organization quality. Besides, do not start with the title and subtitle without a text in between.

Author Response

Dear Reviewer,

Many thanks for your kind work on our manuscript, and we should also express our sincere thanks to your invaluable comments and suggestions which make our manuscript perfect. We have made a thorough revision according to your comments. Our answers are shown as follows:

1. It was impossible for me to identify the novelty of the paper. Please state the novelty of this paper in answer to the comments: Do we have existing studies on an exactly similar topic? What is the specific contribution relevant to existing similar studies? Please provide some references related to similar existing studies and then the authors could state the contribution clearly in the manuscript. Hence, the paper should be revised to highlight novelties. Please consider that this lack of novelty starts with the Abstract, Introduction, and Conclusion.

ANSWER: Done. Thank you for your reminder. We are sorry for the confusion we have not clarified. So we made the follow explanations.

In the field of IPD collaboration, there are a few similar researches on IPD principles influence on the level of collaboration, but the principles selected in some researches are not comprehensive enough (we perfect this selection by adapting the principles from NASFA, E., APPA, A. and AGC, A. (2010), "Integrated project delivery for public and private owners") and most literatures are focused on the improvement of collaboration level (El Asmar M, Hanna A S. Comparative analysis of integrated project delivery (IPD) cost and quality performance). There are also some literatures about IPD principles on project performance, but the research method adopts mainly Structural Equation Model (SEM), whose causal relationship is symmetrical (Mei, T.; Guo, Z.; Li, P.; Fang, K.; Zhong, S., Influence of integrated project delivery principles on project performance in china: An sem-based approach). The three references has cited in the appropriate place in the modified version to support the relevant views.

About the novelty, we have added novelty in abstract, introduction, and conclusion of the modified version, which is similar to the followings.

Considering the deficiency in the previous study, this paper not only filled fills the gap in the field of IPD collaborative management obstacles by the proof by contradiction, but also improves the research methodology based on fuzzy set qualitative comparative analysis and its asymmetry analysis. At the same time, the importance of IPD principles in the process of collaborative management is prioritized to provide a reference for improving the efficiency of collaborative management in practical engineering.

2. In the Introduction section, there is a lack of references for the several pieces of information that the author presented. For example, this part of the study says, “With the increase in technical complexity and the diversification of specifications of these construction projects, the delivery is becoming increasingly fragmented.” Is it a result developed by the author or cited from other works? Please insight and check for the whole manuscript.

ANSWER: Thank you for your reminder. To solve this problem, we make the following explanation:

First, as for the example, we’re sorry for our negligence. This sentence is cited from other works, which is mainly originated from reference 3, we have supplemented it in the reference: Fischer, M., H.W. Ashcraft, D. Reed, and A. Khanzode. Integrating project delivery: John Wiley & Sons, 2017, http://dx.doi.org/10.1002/9781119049272.app04 .

Besides, we have supplemented the literatures citation forgotten by us in the Introduction and Literature Review, which include as follows:

1. Fischer, M., H.W. Ashcraft, D. Reed, and A. Khanzode. Integrating project delivery: John Wiley & Sons 2017, http://dx.doi.org/10.1002/9781119049272.app04 .
2. Gallaher M P , O'Connor A C , Dettbarn J L , et al. Cost Analysis of Inadequate Interoperability in the U.S. Capital Facilities Industry 2004, Retrieved from bfrl.nist.gov/oae/ on Jun. 11, 2009.

Chang C Y , Pan W , Howard R . Impact of Building Information Modeling Implementation on the Acceptance of Integrated Delivery Systems: Structural Equation Modeling Analysis[J]. Journal of Construction Engineering and Management 2017, 143(8), 04017044.1-04017044.10.

4. Ghassemi, R.; Becerik-Gerber, B. Transitioning to integrated project delivery: Potential barriers and lessons learned. Lean Construction Journal 2011, 2011, 32–52.
5. Durdyev, S.; Hosseini, M.R.; Martek, I.; Ismail, S.; Arashpour, M. Barriers to the use of integrated project delivery (ipd):A quantified model for malaysia. Engineering Construction & Architectural 2019, 27, 186–204.
6. 6. Kelly, D. Investigating the Relationships of Project Performance Measures with the Use of Building Information modeling (BIM) and Integrated Project Delivery (IPD). Ph.D. Thesis, Eastern Michigan University, Ypsilanti, MI, USA, 2015. Available online: https://commons.emich.edu/theses/599/ (accessed on 1 November 2021).
7. 7. Elghaish, F.; Hosseini, M.R.; Talebi, S.; Abrishami, S.; Martek, I.; Kagioglou, M. Factors driving success of cost management practices in integrated project delivery (ipd). Sustainability 2020, 12, 9539.
8. 8. Choi, J.; Yun, S.; Leite, F.; Mulva, S.P. Team integration and owner satisfaction: Comparing integrated project delivery with construction management at risk in health care projects. Journal of Management in Engineering 2019, 35(1), 05018014.
9. 9. Hanna, A.S. Benchmark performance metrics for integrated project delivery. Journal of Construction Engineering and Management -Asce 2016, 142, 04016040.
10. 10. Mei, T.T.;Wang, Q.K.; Xiao, Y.P.; Yang, M. Rent-seeking behavior of bim & ipd-based construction project in china. Engineering Construction & Architectura 2017, 24, 514–536.
11. 11. Xu, Y.Q.; Kong, Y.Y. The research status and forecast of ipd in china. Journal of Engineering Management 2016, 30, 12–17.
12. 12. He, Q.; Wang, G.; Luo, L.; Shi, Q.; Xie, J.; Meng, X. Mapping the managerial areas of building information modeling (bim) using scientometric analysis. International Journal of Project Management 2017, 35, 670–685.
13. 13. Whang S W , Park K S , Kim S . Critical success factors for implementing integrated construction project delivery[J]. Engineering, Construction and Architectural Management 2019, 26(10), 2432-2446.
14. 14. W.L. Analysis of impediments to the development of IPD collaborative mode based on BIM -- based on AHP model [J]. Modern Business Trade Industry 2018,39(22):204-206.

3. A deep analysis of recent scientific papers covering only the topic and leading to the submission hypothesis based on the gap analysis of the previously published research is required. This step is necessary to cover all the applied methodologies in the proposed methods of this study.

ANSWER: Done. Thank you for your reminder. We’re sorry for the step forgotten by us. We have made a deep analysis of recent scientific papers covering only the topic in 2.2.2 Summary of Missing Parts in the Current Field of Research, and we also supplemented some references in this part to analysis the current research status.

And the analysis of recent scientific papers leading to the submission hypothesis. The three kinds of principles were proposed based on the reference Integrated project delivery for public and private owners. IPD principles include contractual principles, behavioral principles and catalysts for IPD. This category is derived from the page 6~7 of reference [11]. The hypothesis is proposed mainly based on this literature.

11. NASFA; COAA; APPA; AHEFO; AGC; AIA, Integrated project delivery for public and private owners. 2010. (pp:6~7)：

And the proposed method fuzzy set qualitative comparative analysis (fsQCA) which is a type of qualitative comparative analysis in this study. Qualitative comparative analysis (QCA) is a method mainly applied in the field of management in recent years, which overcomes the disadvantages of the traditional linear regression model and the causal symmetry of structural equation model ([1] Cheng, J;Luo, J;Du, Y;Liu Q, What kinds of entrepreneurial ecosystem can produce country-level female high entrepreneurial activity?; [2] Zhang M; Du Y, Qualitative Comparative Analysis (QCA) in Management and Organization Research: Position, Tactics, and Directions ; [3] Du, Y.; Kim, P.H., One size does not fit all: Strategy configurations, complex environments, and new venture performance in emerging economies .). Due to the manuscript word count requirement, this part didn’t shows in the main text.

4. I would suggest adding the questionnaire survey as a supplementary file in order to facilitate the understanding of issues for the readers.

ANSWER: Done. Thanks for your suggestion. We have provided the questionnaire survey in the following and added the questionnaire survey as an appendix in the Modified version.

Appendix A: Questionnaire on the Implementation of IPD Principles (I) [English version]

Dear experts/professionals,

Thank you very much for taking the time to participate in this questionnaire. Thank you for your support and help. This questionnaire is only for academic research, anddoes not have any commercial use, nor will it disclose any of your privacy.We will obey the requirements of information confidence, and the questionnaires are anonymous. Please feel free to fill in the anonymous questionnaire! Your selection has a decisive impact on this study. Therefore, please spare your precious time in your busy schedule to answer the relevant questions of this questionnaire and correct the shortcomings. Thank you for your support and wish you a happy work!

Part 1 Basic Information

1. What is your age? ( )

2. What is your educational background? ( )

3. What's your professional title? ( )

4. What is your employment unit? ( )

5. How many years have you worked in the construction industry? ( )

6. How many BIM projects have your experienced? ( )

7. What is your willingness to use BIM technology? ( )

Part 3 IPD information survey

Integrated Project Delivery (IPD) is a project delivery approach that integrates people, systems, business structures, and practices into a process that collaboratively harnesses the talents and insights of all participants to optimize project results, increase value to the owner, reduce waste, and maximize efficiency through all phases of design, fabrication and construction.

1. How familiar are you with IPD? ( )

2. Based on your experience in the BIM project and the implementation of the actual project, what do you think is the impact of the following IPD principles on information collaboration? ( )

3. What stage of collaboration do you think our industry is in now ( )

5. The proposed approach in section (3) is not outlined with the necessary vigor. The author needs to include sufficient methodological details in the paper and elaborate on the produced results from the proposed methods. Some sections must be added and others need to be relocated and rewritten to make it clearer for the readers. Besides, Figure 3 must be explained and justified better in the text.

ANSWER: Done. Thanks for this good question. We make the following explanations for details.

First, about the proposed approach questionnaire survey in section (3), we added the origin of variables selection to prove the rationality of questionnaire, and we supplemented questionnaire access time in 3.2.2 and introduced the contents of questionnaire in the appendix. Besides, we added a table to clarify the respondents we surveyed as follows.

Table 3. Three main ways to distribute the questionnaire

About the proposed approach fsQCA in section (3), we also introduced two indictors of evaluating fsQCA results in 3. 3 Line 361-366.

  Consistency and coverage are the two main indictors to reflect the reliability of the results. Consistency refers to the degree of consistency between the conditional variable or path and the result. Coverage refers to the extent to which a condition or path subset physically covers the conditions or paths sets.

Second, about the produced results from the proposed methods, we updated some descriptive statistics on the recovered data and added some content appropriately in 4.1.2 and 4.1.3.

About Tables 3 (now table 4), we have described as follows:

The background distribution of respondents was analyzed, as shown in Table 4. Respondents were mainly chosen from construction units, design units, and universities and research institutions, and the proportion of every unit is relative balanced and covers a wide range. Moreover, more than two third of the respondents were engaged in the construction industry for more than three years and nearly half of them have participated in more than three BIM projects, respondents with long-term industry experience and sufficient BIM project experience make their responses have reference significance for related research. In addition, nearly 90% of the respondents have a strong desire to use BIM technology. As BIM is the basis for the rapid development of the IPD, the participants working on BIM projects and their strong willingness to use BIM have a strong reference for the analysis of the IPD project collaboration.

About Tables 4 (now table 5), we have added as follows in Line421-425 in 4.1.3:

Respondents that are inexperienced and unfamiliar with IPD accounts for 38.3% of the total, respondents who are inexperienced though informed about IPD accounts for 44.7% of the total and respondents who are experienced with IPD accounts for 17% of total.

About the produced results from fsQCA, we updated some descriptive statistics on the recovered data and added some content appropriately in 4.2.2 and 4.2.3.

About Tables 5 (now table 6), we have rewritten the original paragraph as follows in Line457-474 in 4.2.2 and added a note to explain the table 6:

The necessary conditions of a single factor are obtained, as shown in Table 6. Consistency is similar to the coefficient significance degree (p-value) in regression analysis, which refers to what extent a certain result requires the existence of a certain variable. Coverage refers to the extent to which a subset physically covers the target set, which is a direct indicator of the empirical importance of antecedent conditions. In fact, when the consistency is below 0.9, neither sample has a bottleneck yet there is little collaboration [15, 16]. As can be seen from Table 5, the necessary conditions were absent in both the overall sample and sample 1. Although in samples 2 and 3, the necessary conditions (contractual principles, behavioral principles and catalysts for IPD in sample 2; catalysts for IPD in sample 3) of low collaboration level exist, but the low coverage of necessary conditions less than 0.8 means that these subsets don’t account for a large proportion of the total. Therefore, the multiple antecedent conditions need to be combined for configuration analysis in this study.

About Tables 6 (now table 7), we can use another table form which doesn’t show in the main text to express the contents of Table 6 (now table 7), we also have added 4 paragraphs to describe the different paths in 4 samples in Line503-532 in 4.2.3 before table 7 as following:

Legend: A sideways tilde ~ indicates the absence or negation of the causal condition. An asterisk * indicates conjunctive. ~Contractual Principles indicates that the condition is a core condition, and ~Contractual Principles indicates that the condition is an edge condition.

In overall sample, which includes all respondents, there exist 2 configuration paths. Path S1A shows that contractual principles is absent as the core condition, whereas behavioral principles and catalysts for IPD have no impact on low collaboration level. Concerning the path S1B, it indicates that behavioral principles is absent as the core condition, catalysts for IPD exists as the edge condition, and contractual principles has no impact on low collaboration level.

In sample 1, which includes the respondents that are inexperienced and unfamiliar with IPD, there exists 1 configuration path. Path 2 shows that contractual principles, behavioral principles and catalysts for IPD are all absent as the core conditions for low collaboration level.

In sample 2, which includes the respondents who are inexperienced though informed about IPD, there exist 2 configuration paths. Path S3A indicates that behavioral principles is absent as the core condition, catalysts for IPD exists as the edge condition, and contractual principles has no impact on low collaboration level. Path S3B shows that contractual principles and catalysts for IPD are absent as the core condition, behavioral principles exists as the edge condition.

In sample 3, which includes the respondents who are experienced with IPD, there exist 2 configuration paths. Path S4A shows that contractual principles is absent as the core condition, behavioral principles exists as the edge condition, and catalysts for IPD has no impact on low collaboration level. Path S4B indicates that behavioral principles is absent as the core condition, catalysts for IPD exists as the edge condition, and contractual principles has no impact on low collaboration level.

Finally, we also have improved figure 3 and explained and justified it better in the text.

6. The Discussion section should be improved by including a clear and concise analysis of all results presented in the previous section rather than comparing them with the results of previous research. It might be helpful to use more figures to present the results.

ANSWER: Thanks for your kind remind. To solve this problem, we make the following explanations:

First, the necessity analysis was discussed in Line 565-571 as follows.

The necessity analysis results do not have the necessary conditions with relatively high coverage, corresponding to the configuration paths in one sample does not have the same conditional level of necessary conditions, so necessity analysis has no practical significance for the interpretation of the final configuration path.

Second, the configuration analysis was discussed in Line 571-586 as follows.

In four groups of samples in this paper, seven concurrent obstruction paths, under four groups of samples, seven concurrent obstruction paths were obtained by FS-fsQCA. In fact, there are only five different paths obstructing the level of collaboration. The first path only consists of the absence of contractual principles which is the core condition. The second path consists of the absence of behavioral principles which is the core condition and the presence of catalysts for IPD which is the edge condition. The third path consists of the absence of three kinds of principles which are all core conditions. The forth path consists of the absence of contractual principles and catalysts for IPD which are both core conditions, and the presence of behavioral principles which is the edge condition. The fifth path only consists of the absence of contractual principles which is the core condition and the presence of behavioral principles which is the edge condition.

Besides, we can use another table form which doesn’t show in the main text to express the results of configuration analysis as follows. And we also added some literatures in theDiscussion to support our conclusions from another more holistic view.

Legend: A sideways tilde ~ indicates the absence or negation of the causal condition. An asterisk * indicates conjunctive. ~Contractual Principles indicates that the condition is a core condition, and ~Contractual Principles indicates that the condition is an edge condition.

7. Please try to avoid using the numerical way in presenting the results in the Conclusion section.

ANSWER: Thanks for this good suggestion. We have removed the most numerical way in presenting the results in the Conclusion section. In detail, the most numerical way in Line 712-713, theoretical contribution and practical contribution has been removed. However, the most numerical way in 6.3 Limitations and Future Research Directions was retained to distinguish between different limitations and directions after emerging the original paragraphs, and I hope this solution is also suitable for your suggestion.

8. Proofreading by a native English speaker should be conducted to improve clarity and organization quality. Besides, do not start with the title and subtitle without a text in between.

ANSWER: Thanks for this suggestion. To solve this problem, we make the following explanations:

First, we have checked and corrected the language in the full text to improve clarity and organization quality, please check the modified version.

Second, about the problem of starting with the title and subtitle without a text in between, we make the following explanations: (1) Due to our incorrect use of symbols and irregular abbreviations of nouns, we apologize sincerely for confusing you with our negligence. We want to clarify that there are no subtitles in the main text in fact and we have corrected the wrong symbols and abbreviations, please check the modified version. (2) There is another situation in the text. When a word was not fully spelt on one line, we used a dash to carry on the word to be spelt on the next line like sub-title, which was corrected by adjusting the alignment of the left and right sides of the text and adding and deleting words as appropriate in the modified version, please check.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

The second submission is definitive an improvement to the first submission.

General and style comments:

Several times 3 items are connected with "and" and the comma after the second item is missing.

Line 90ff:
"This study not only fills the gap in the field of IPD collaborative management obstacles, but also improves the research methodology based on fuzzy set qualitative and quantitative comparative analysis and model asymmetry analysis."
How can this study "fill the gap in the filed of ... obstacles"?
And why does it "improve the research methodology?

It uses a research methodolgy.

Line 110:
The phrase "117 complete literature" is misleading. This might be "117 publications in total", but not the complete literature.

Figure 1 and Figure 2:
It is not surprising that the main clusters are "ipd" and "collaboration", because you were looking for papers with theses phrases.

Line 131:
It is unclear what you mean with: "almost the same results have been obtained will going through two well-known databases"

Line 183:
Between 3.2 and 3.2.1 should be introductory text.

Line 198:
How can the paper "summarizes the management enlightenment"?

Line 229:
"This paper proposes initially 15 IPD principles"
Aren't they taken from another publication? 
Hence, not this paper proposes the principles.

Table 3
lists "CNKI, WANFANG, CQVIP" -- it is not clear, what these phrases mean.

Line 283 and 284:
Between 4. and 4.1 as well as 4.1 and 4.1.1 should be introductory text.

Line 325:
Between 4.2 and 4.2.1 should be introductory text.

Line 345:
" ... from Table 5, the necessary ..."
That should be "Table 6"

Table 6:
Only part of the table can be seen.

Line 363ff:
Several results are listed -- but: What do they mean? What can we do with these numbers? 

New line numbering starting from page 14:
Line 131:
The first sentence misses the word "in".

Line 225:
Reference 8:
Aus authors "NASFA, E., APPA, A. and AGC, A." are listed. This are organizations which do not have a first name -- and two organizations are missing. Should be: "NASFA, COAA, APPA, AGC, AIA" 

Line 242:
Should be "ASCE" instead of "Asce".

Line 252:
Should be "—" instead of "--"

Line 264 (Reference 28):
Information is missing.

Line 294:
2 times "2012"?

Author Response

Dear Reviewer,

Many thanks for your kind work on our manuscript, and we should also express our sincere thanks to your invaluable comments and suggestions which make our manuscript perfect. We have made a thorough revision according to your comments. Our answers are shown as follows:

Reviewer #1:

1. Several times 3 items are connected with "and" and the comma after the second item is missing.

ANSWER: Done. Thank you for your reminder. We have supplemented the missing commas after the second item in the whole manuscript, please check.

2. Line 90ff: "This study not only fills the gap in the field of IPD collaborative management obstacles, but also improves the research methodology based on fuzzy set qualitative and quantitative comparative analysis and model asymmetry analysis." How can this study "fill the gap in the field of ... obstacles"? And why does it "improve the research methodology? It uses a research methodology.

ANSWER: Done. Thank you for your reminder. We are sorry for the confusion we have not clarified, so we made the follow explanations.

In the field of IPD collaboration, there are a few similar researches on IPD principles influence on the level of collaboration, but the principles selected in some researches are not comprehensive enough (we perfect this selection by adapting the principles from NASFA, E., APPA, A. and AGC, A. (2010), "Integrated project delivery for public and private owners") and most literatures are focused on the improvement of collaboration level (El Asmar M, Hanna A S. Comparative analysis of integrated project delivery (IPD) cost and quality performance). Based on the proof by contradiction, this paper studied the constraints of applying the IPD principles to the level of collaboration of construction projects and expanded the research to show the problems of IPD model in the field of collaborative management. In addition, this paper considered the influence of the combination of contractual principle, the behavioral principle, and the catalysts for IPD on the level of collaboration in project construction.

There are also some literatures about IPD principles on project performance, but the research method adopts mainly Structural Equation Model (SEM), whose causal relationship is symmetrical (Mei, T.; Guo, Z.; Li, P.; Fang, K.; Zhong, S., Influence of integrated project delivery principles on project performance in china: An sem-based approach). The three references has cited in the appropriate place in the modified version to support the relevant views. And the proposed method fuzzy set qualitative comparative analysis (fsQCA) which is a type of qualitative comparative analysis in this study. Qualitative comparative analysis (QCA) is a method mainly applied in the field of management in recent years, which overcomes the disadvantages of the traditional linear regression model and the causal symmetry of structural equation model. This paper enriches the research methods of IPD mode in the field of IPD collaborative management, which analyzes the influencing factors that obstruct the level of collaboration of construction projects from the perspective of "induction-tracing". In addition, configuration analysis is an asymmetric analysis and it shows that the combination of one or more conditions constitutes the antecedent of a specific result.

About the novelty, we have added novelty in abstract, introduction, and conclusion of the modified version, which is similar to the followings.

Considering the deficiency in the previous study, this paper not only filled fills the gap in the field of IPD collaborative management obstacles by the proof by contradiction, but also improves the research methodology based on fuzzy set qualitative comparative analysis and its asymmetry analysis. At the same time, the importance of IPD principles in the process of collaborative management is prioritized to provide a reference for improving the efficiency of collaborative management in practical engineering.

3. Line 110: The phrase "117 complete literature" is misleading. This might be "117 publications in total", but not the complete literature.

ANSWER: Thank you for your reminder. We’re sorry for the confusion, to solve this problem, we make the following explanation:

Due to lack of author information in some literatures searched on CNKI, a total of 117 literatures with complete information were retained after removing literatures with incomplete information. We have adjusted in the line 133, please check.

4. Figure 1 and Figure 2: It is not surprising that the main clusters are "ipd" and "collaboration", because you were looking for papers with theses phrases.

ANSWER: Done. Thank you for your reminder. We are sorry for the confusion we have not clarified, so we made the follow explanations.

The bibliometric analysis is to find other research hotspots in the field of IPD and collaboration. Although it is stated in the paper that IPD and collaboration are the main clusters, it only reflects the content in the figure, and more importantly, it expands other clusters such as collaborative management and BIM.

5. Line 131: It is unclear what you mean with: "almost the same results have been obtained will going through two well-known databases".

ANSWER: Done. Thanks for your suggestion. We sincerely apologize for the wrong presentation. We have replaced the sentence with “almost the same results have been obtained through the bibliometric analysis of literatures on related topics from well-known databases” in line 158-160. Through the bibliometric analysis of literatures on related topics, the same results that the clusters including collaborative management and BIM are both shown in Figure 1 and Figure 2 have been obtained and will be discussed in section 2.2.

6. Line 183: Between 3.2 and 3.2.1 should be introductory text..

ANSWER: Done. Thanks for this good suggestion. We have added a small paragraph as introductory text between 3.2 and 3.2.1 to facilitate the understanding issues, please check line 221-224.

7. Line 198: How can the paper "summarizes the management enlightenment"?

ANSWER: Done. Thanks for your kind remind. To solve this problem, we make the following explanations:

This paper summarizes the management enlightenment through prioritizing the importance of IPD principles and demonstrating the importance of understanding of IPD mode. Appropriately increasing the familiarity of practitioners with IPD will promote for better application of IPD model and high level of collaboration in construction projects, and the contractual principles take priority over the behavioral principles which also take precedence over the catalysts for IPD in the promotion of collaboration level.

8. Line 229: "This paper proposes initially 15 IPD principles" Aren't they taken from another publication? Hence, not this paper proposes the principles.

ANSWER: Done. Thanks for this good suggestion. We apologize for the wrong presentation. These 15 IPD principles are taken from another publication, so we replaced the word ‘proposes’ with ‘adopts’ in line 284.

9. Table 3: lists "CNKI, WANFANG, CQVIP" -- it is not clear, what these phrases mean.

ANSWER: Done. Thanks for this suggestion. To solve this problem, we make the following explanations:

China National Knowledge Infrastructure (CNKI, https://www.cnki.net/ ) is the world's largest database of Chinese knowledge resources.

WANFANG (https://www.wanfangdata.com.cn/index.html ) is a large-scale network database covering journals, conference minutes, papers, academic achievements and academic conference papers. It is also a professional academic database in China as famous as CNKI.

CQVIP (http://lib.cqvip.com/ ) is a periodical big data service platform with Chinese periodical resource guarantee as the core, data retrieval application as the basis, data mining and analysis as the feature, and multi-scenario application for teaching, learning, production, research and other applications.

Through these three largest Chinese databases, we obtained the contact information of the corresponding authors of published studies, and then invited these authors to fill in the questionnaire through email to ensure the reliability of the questionnaire data.

10. Line 283 and 284: Between 4. and 4.1 as well as 4.1 and 4.1.1 should be introductory text.

ANSWER: Done. Thanks for this suggestion. We have added a small paragraph as introductory text between 4 and 4.1 as well as 4.1 and 4.1.1 to facilitate the understanding issues, please check line 341-343 and 345-347.

11. Line 325: Between 4.2 and 4.2.1 should be introductory text.

ANSWER: Done. Thanks for this suggestion. We have added a small paragraph as introductory text between 4.2 and 4.2.1 to facilitate the understanding issues, please check line 401-404.

12. Line 345:" ... from Table 5, the necessary ... "That should be "Table 6".

ANSWER: Done. Thanks for this reminder. We have corrected this error, please confirm in line 425.

13. Table 6: Only part of the table can be seen.

ANSWER: Done. Thanks for this remind. We have made adjustments to Table 6 to make sure the whole part of the table can be seen, please check.

Table 6. Analysis of antecedents’ necessary condition under multiple samples

Note: A sideways tilde ~ indicates the absence or negation of the causal condition. CY indicates the consistency between the condition variable and low level of collaboration, CE indicates the coverage between the condition variable and low level of collaboration.

14. Line 363ff: Several results are listed -- but: What do they mean? What can we do with these numbers?

ANSWER: Done. Thanks for this suggestion. To solve this problem, we make the following explanations:

These results describe the distribution of the sample data, which is the basis for further analysis. These numbers shows the authenticity and reliability of the data to a certain extent, and the authenticity of the data ensures the reliability of the following analysis.

15. New line numbering starting from page 14:

ANSWER: Done. Thanks for this remind. We have adjusted line numbers to ensure the continuity of line numbers throughout the manuscript, please check.

16. Line 131: The first sentence misses the word "in".

ANSWER: Done. Thanks for this remind. We have added the missing word "in", please check.

17. Line 225: Reference 8: Aus authors "NASFA, E., APPA, A. and AGC, A." are listed. These are organizations which do not have a first name -- and two organizations are missing. Should be: "NASFA, COAA, APPA, AGC, AIA"

ANSWER: Done. Thanks for this remind. We have corrected this error, please confirm in line 793.

18. Line 242: Should be "ASCE" instead of "Asce".

ANSWER: Done. Thanks for this remind. We have corrected this error, please confirm line 814.

19. Line 252: Should be "—" instead of "--".

ANSWER: Done. Thanks for this remind. We have corrected this error, please confirm line 828.

20. Line 264 (Reference 28): Information is missing.

ANSWER: Done. Thanks for this remind. We have added the missing information in the reference 28, please confirm line 842-843.

21. Line 294: 2 times "2012"?

ANSWER: Done. Thanks for this question. The latter "2012" in reference 44 represents the number of pages in the reference.

Author Response File: Author Response.pdf

Reviewer 2 Report

The work has developed and the author met most of my previous comments. I just would like to ask to avoid starting with the title and subtitle without a text in between. For example, between seciton (2) and subseciton (2.1.), I would suggest adding a small paragraph that could explain to the reader what will  find in this part of the study in order to facilitate the understanding issues. The same comment is applicable for section (4) and subsections (4.1.) and (4.1.1.). Please check for the whole manuscript. 

Author Response

Dear Reviewer,

Many thanks for your kind work on our manuscript, and we should also express our sincere thanks to your invaluable comments and suggestions which make our manuscript perfect. We have made a thorough revision according to your comments. Our answers are shown as follows:

Reviewer #2:

1. The work has developed and the author met most of my previous comments. I just would like to ask to avoid starting with the title and subtitle without a text in between. For example, between section (2) and subsection (2.1.), I would suggest adding a small paragraph that could explain to the reader what will find in this part of the study in order to facilitate the understanding issues. The same comment is applicable for section (4) and subsections (4.1.) and (4.1.1.). Please check for the whole manuscript..

ANSWER: Done. Thank you for your suggestion. After checking the whole manuscript, we have added a small paragraph as introductory text between 2 and 2.1, 3.2 and 3.2.1, 4 and 4.1, 4.1 and 4.1.1 as well as 4.2 and 4.2.1 to facilitate the understanding issues, please check. However, between the section (3) and subsection (3.1.), we think it better not to add the introductory text to avoid repetition with the contents in Section 3, please understand.

Author Response File: Author Response.pdf