## 3 CSFs for Construction Projects in EFRs
### Identification of CSFs  
There are two steps to identify and extract CSFs: (1) identifying CSFs through a literature review; (2) extracting CSFs by semi-structured interviews on a practical construction project (i.e., DREWP in KC of China). First, we conducted a process of literature collection based on two types of database: Scopus and Web of Science. Two types of key words such as \"construction project\" and \"environmentally fragile regions\" are settled for the search strategies including title, abstract and keywords. The time span is settled to \"2000 to 2021\". As a result, 246 articles are collected and prepared for the next screening process. After the screening process, including: (1) removal of the duplicate articles; (2) filtering of the articles according to the correlation toward the title, abstract and full-text etc. ; (3) replenishment of the omission articles from the references cited in the remaining ones. Finally, 30 articles related to the CSFs for a construction project in EFRs are identified. The CSFs in these 30 articles are dispersed and have various descriptions, which may not specifically be related to the construction project conducted in EFRs. For instance, \"resources of water\" may not be critical in non-EFRs. \"Sustainable strategies\" were differently prioritized between EFRs and non-EFRs. The solutions to reducing the impact on the local ecological environment from construction activities and to adapting to the fragile environment are described as a strategy for practicing sustainable construction projects, etc. Hence, it is necessary to consider the extracted CSFs into a specific scenario, the construction project conducted in EFRs. We designed and carried out semi-structured interviews with 20 experts and key project participants (KPPs) to obtain a detailed and consistent description for each CSF for construction project in EFRs. These KPPs play different roles and have essential positions in the DREWP, e.g., the chief engineer, project contractor, site personnel, safety and quality supervision, business manager, designer and supervisors from URPA etc. They are asked to accomplish two crucial tasks: (1) finalizing the CSFs with the consistent description by a careful review of the whole process and the main work to which they contributed in the DREWP project, and (2) determining the causal relationship between any two CSFs through pairwise comparisons with the experience and knowledge of these KPPs. Some similar descriptions of CSFs from the literature are categorized. For instance, \"the clear definition of responsibilities\" [94] and \"a clear understanding of roles\" [22] are both identified as a description of the CSF in the collected 30 articles. Therefore, a combination could be made correspondingly. The finalized CSFs for a construction project in EFRs and their source of data are presented in Table 1. Three rounds of discussion were made to arrive at the conclusion by each KPP and their determinations are recorded to form a causal relationship network (presented in Figure 3), which will be used in the next steps for the ISM. A list of 18 CSFs for construction projects in EFRs was collected based on the combination of a literature review of collected references and a case study on the DREWP project, followed by additional screening and a combination of relevant information. Table 1 provides the list of 18 collected CSFs. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Code (i)** & **Critical Success Factor** & **Source of Data** \\ \hline
1 & Professionalism of partners & [46; 93; 95] \\
2 & Partnering experience & [22; 24; 94] \\
3 & High credibility of partners & [94; 96] \\
4 & Effective and open internal and external communication & [22; 24; 97] \\  & and collaboration & \\
5 & Mutual trust & [22; 23; 24; 61; 97; 98] \\
6 & Clear definition of responsibilities & [22; 99; 100] \\
7 & Conflict resolution & [24; 70; 97] \\ \hline \hline \end{tabular}
\end{table} 
Table 1: CSFs for construction projects in ecologically fragile regions.