**4. Identifying the Critical Parameters Affecting the Estimation of Overall Risk at the Conceptual Stages**

Literature analysis and earlier research yielded eleven criteria that can be utilized to forecast overall risk in residential projects. Floor space, number of floors, slab type, interior finishes, number of elevators, external finishes, electromechanical type, number of basements, foundation type, risk management implementation, and overall project duration are some of the elements to consider. Five experts with at least 15 years of experience in residential project management used the Delphi technique to select the final parameters. Table 3 shows the demographic information about the experts. The experts were requested to add missing parameters, if any, that could affect the overall risk and could be discovered at a conceptual stage, in the first round. There is no missing factor according to the experts' responses. On a five-point Likert scale, the experts were asked to evaluate the weight of each parameter in the second round. "1" indicates that this element is inconsequential; "2" suggests low importance; "3" indicates moderate significance; "4" indicates high significance; and "5" indicates extremely significant. Equation (1) was used to calculate the relative relevance index based on the responses received. Table 4 displays the relative importance indexes. The lowest number on the Likert scale is "1," and the highest is "5", resulting in a range of four, which will be graded according to the five categories. The zone for each category is 0.8. The very low category has a range of 1 to 1.8. The low category has a range from 1.8 to 2.6, while the range of the medium category is from 2.6 to 3.4. The high category is from 3.4 to 4.2, whereas the very high category is from 4.3 to 5.0.

$$RII = \frac{\sum W}{AN} = \frac{(5n\_5 + 4n\_4 + 3n\_3 + 2n\_2 + 1n\_1)}{5N} \tag{1}$$

**Table 3.** Demographic data regarding the experts.



**Table 4.** The relative importance indices of critical parameters.

The five experts agreed that the total duration of the project and the number of floors are the most important factors, with relative importance indices of 4.4 and 4.2, respectively, followed by the floor area, which has a relative importance index of 3.6. Experts agreed that the risk management application and the type of electromechanical factors are considered to have a medium effect on the cost estimation. While the factors of interior finishes, exterior finishes, and the number of basements were considered to have a low impact on cost estimation by experts. Whereas slab type, elevator number, and foundation type had very low impacts on cost estimation. As a result, any factor with an RII of less than 1.8 was eliminated from the final list. As a result, the slab type, elevator number, and foundation type were left off the final list of parameters influencing the total risk prediction in the conceptual stages. The final set of criteria consisted of the remaining eight parameters. Experts were asked to assess whether or not they agreed with the finalist list in the third round. Regarding the final list of criteria, which includes the remaining eight criteria, the experts agreed unanimously.
