Journal of Civil Engineering Vol 68 No 2

Journal of the South African Institution of Civil Engineering Volume 68 Number 2 June 2026 11 and performance evaluation criteria corresponds to a 0.452-unit increase in enhanced contractor capabilities and pro- ject performance. Statistical significance was assessed using t-statistics and p-values. Contractor grading evaluation results Using AHP, the derived priority vector indicates that technical capacity is the most important criterion, followed by experience and past performance, occupational health and safety (OHS), financial status, plant and equipment, and, lastly, management capability. Figure 8 illustrates the weights of the main criteria, as calculated using Equations 1 to 3 above. The results of the overall project priority vector, in relation to the over- arching goal of contractor grading and performance assessment, are presented in Tables 4 and 5. Table 4 shows the overall weights (V) for contractor grades (options 1 to 9) as 0.040, 0.094, 0.096, 0.102, 0.105, 0.120, 0.124, 0.153, 0.164. Table 5 presents the overall priority vector for contractor performance assessment, with weights of 0.151, 0.288, and 0.534. Figure 9 depicts that grade 9 has the overall highest priority weight (Equation 3) of 0.164, with the overall priority matrix of 0.140, 0.094 ,0.096, 0.102, 0.105, 0.120, 0.124, and 0.153 for the respective lower grades. A sensitivity analysis was conducted on six scenarios to check the reliability and robustness of the AHP results. Sensitivity analysis is an analytical method that is used to identify how much variations in the input values for a given variable will impact the results of a mathematical model. When Table 6 Overall weights of grading alternatives Priority matrix for contractor grades Overall project priority vector V Main criteria priority vector Alternatives Technical capacity Experience P&E Financial status Past performance Management capability OHS Technical 0.380 G1 0.077 0.014 0.020 0.028 0.014 0.030 0.026 0.040 Experience 0.199 G2 0.081 0.123 0.020 0.030 0.123 0.030 0.122 0.094 P&E 0.038 G3 0.081 0.123 0.020 0.046 0.123 0.030 0.122 0.096 Financial status 0.071 G4 0.094 0.123 0.059 0.053 0.123 0.030 0.122 0.102 Past performance 0.199 G5 0.094 0.123 0.059 0.086 0.123 0.030 0.122 0.105 Management capability 0.023 G6 0.118 0.123 0.126 0.099 0.123 0.126 0.122 0.120 OHS 0.090 G7 0.118 0.123 0.126 0.163 0.123 0.126 0.122 0.124 G8 0.167 0.123 0.285 0.189 0.123 0.223 0.122 0.153 G9 0.167 0.123 0.285 0.304 0.123 0.373 0.122 0.164 Overall priority matrix 0.18 0.16 0.14 0.12 0.10 0.08 0.06 0.04 0.02 0 Grading alternatives 1 2 3 4 5 6 7 8 9 Figure 9 Weights for the overall priority matrix for grading alternatives Grading ranking Scenario A Scenario F Scenario E Scenario D Scenario C Scenario B Grades 1 2 3 4 5 6 7 8 9 0.25 0.15 0.20 0.10 0 0.05 0.047 0.038 0.040 0.040 0.030 0.041 0.102 0.088 0.094 0.094 0.076 0.095 0.089 0.096 0.096 0.078 0.096 0.104 0.097 0.102 0.102 0.087 0.103 0.112 0.100 0.105 0.105 0.091 0.105 0.114 0.119 0.120 0.120 0.120 0.120 0.133 0.125 0.124 0.124 0.129 0.124 0.137 0.161 0.153 0.153 0.176 0.152 0.174 0.180 0.164 0.164 0.214 0.163 0.185 Figure 10 Sensitivity analysis of the six different scenarios for grading alternatives