The AHP analysis begins with the establishment of the hierarchy structure of risk register. In this research, it divided into two levels. Second level covered all of risks based on the result of risk identification phase, there are XXX risks which may be perceived by the main contractor relating to hire subcontractors. The first level is obtained from a brainstorming session to classify the identified risk into several groups. The risks were classified into XX group based on its characteristic and relevant among each other.
The data is obtained by developing questionnaire which contained of pair-wise comparison among the second level members within each group and among the first level members. The respondents are asked to compare each criterion and give the score. There are 14 respondents on this research.
According to the score of the comparison in questionnaire, the matrix is developed. The establishment of the matrix is described as follow:
MATRIX
Saaty (SSS) developed four methods to calculate the eigenvector. In this research, the 4th method is selected considering its accuracy although the complexity of calculation also increases. The calculation of eigenvector is described below:
EIGEN VALUE
From the eigenvector result, we can conclude that the XXX is the most critical risk under XX criteria. Saaty (SSSS) also require consistency test in AHP calculation. The consistency can be determined from Consistency Ratio (CR). The calculation test is provided below:
CR CALCULATION
From 14 respondents, the consistency ratio in each level is varying. No respondent have an acceptable CR in every criteria. The requirement of AHP if the consistency index is not acceptable is we should ask the respondent again to remind their answer and explain a little bit about inconsistency of their answer. In this research, there are 2 respondents which have an acceptable CR in almost of their answer. Respondent 7 should remind his answer in 4 criteria while Respondent 8 should remind his answer in only 2 criteria. After ask again to remind his answer, only Respondent 8 could revise his answer.
The respondents’ answers which don’t have an acceptable CR will not be considered as the data, so the data of each criterion will be varied. This data will be averaged and a new matrix is established. The AHP calculation to get eigenvector and consistency test is conducted