Commissioning risk early warning for power grid projects based on a stratified extended Cox model

To address differences in commissioning duration, right-censored observations, and time-varying risk effects in power grid projects, 172 35–220 kV power grid projects in one city of Jiangsu during the 14th Five-Year Plan period were analyzed. The Kaplan-Meier method and a stratified extended Cox model were used to evaluate commissioning risk and its association with investment deviation. The results showed that the median commissioning duration was 4.34 years and that the time-varying model provided a significantly better fit than the static model. The weighted absolute investment deviation rate of the high-risk group was 20.22 percentage points higher than that of the low-risk group. The proposed approach can provide quantitative support for early screening of commissioning risk and dynamic adjustment of investment plans.