they are the best candidates for validation and verification of the empirical results. After hours of
discussion and interview with the managers in several meetings, they conclude that the obtained
results are valid and reliable. Also, we asked each of the experts to assign a value (which ranges
from 0 to 1), to impact degree of RE principles on HSEE factors. The results of impact degrees
of RE principles on HSEE factors obtained by FCM as well as experts are shown in Figure 5