## 6 Discussions  
Figure 4 illustrates a clear hierarchy of CSFs and shows that the 18 CSFs have strong interrelationships. For instance, it is demonstrated that CSF17 (the project manager's leadership style) and CSF18 (economic viability) are the root factors, as expected, and have a profound influence on other CSFs. CSF17 promotes the CSF14 (organizational project culture) and CSF18 contributes to CSF13 (facilitator). There is some evidence in prior studies on the relationship between the project manager's leadership style and the organizational project culture [105; 106; 107; 108]. [PERSON] [109] proposed that the organizational project culture is the bridge between different elements of project organization and enhances their cohesion. This is supported by the findings that an appropriate leadership style can lead to better project performance and increases in levels of leadership may enhance relationships among team members [71]. CSF18 (economic viability) is another CSF which has a direct influence on the CSF13 (facilitator). Economic viability can provide necessary resources and stimulations to build a strict incentive system, such as funds or rewards for participants [110; 111; 112]. Furthermore, this strict incentive system plays an important role in organizing a construction crew to work in an extremely poor ecological environment. Meanwhile, [PERSON] et al. [113] argued that the establishment of an incentive mechanism must meet the needs of the stakeholder, legitimately allocate resources, and reduce the cost risk. Once the economic conditions meet the requirements, sufficient resources are then applied to establish an incentive mechanism by PMT [24; 46]. Figure 5: The MICMAC analysis for classification of CSFs. CSF (conflict resolution), CSF11 (planning and implementation of sustainable strategies) and CSF15 (resources of water) are the direct factors appearing at the top level of ISM. Establishment and communication of a conflict resolution strategy, such as joint problem solving [94; 98], can benefit the project manager to establish a sound harmonious teamwork. As is presented in ISM, CSF7 (conflict resolution) is influenced by two CSFs which are the CSF4 (effective and open internal and external communication and collaboration) and the CSF6 (a clear definition of responsibilities). This means that we could make the conflict resolution by carrying out effective communication and collaboration and have a clear understanding of the roles for each of the project's participants. For instance, [PERSON] and [PERSON] [114] raised the suggestion that the project manager should undertake the responsibility of organizing, selecting and defining the responsibilities of the PMT. The most significant point is that the project manager should clearly have a knowledge of their responsibilities as the leader of a PMT and have proficient management skills and authority in the control of personnel [115; 116; 117]. CSF11 (planning and implementation of sustainable strategies), appearing at the top level of ISM, is influenced by CSF10 (responsiveness to external environmental changes) and CSF12 (policy support on the protection of the local ecological environment). The adaptation and sustainability of buildings to the natural ecological environment should be important research issues in the future. According to the different types of external ecological environment, it is noticed that in the adjustments and changes in construction methods, the implementation of environmentally friendly and sustainable building materials [118; 119; 120], and the reduction in environmental pollution [121] and damage by limited building emissions [122; 123; 124], are critical success factors for the construction projects in EFRs. Finally, through the MICMAC analysis, the CSFs for construction projects in EFRs were classified. It is presented that there are no CSFs located at the linkage quadrant. The autonomous quadrant consists of the majority of CSFs (11 out of 18) with both weak driver and dependence powers.