In 2011 Kramadibarata et al. curve slope stability has been developed using dimensional analysis as applied to open pit coal. In principle, the stability curve has been able to answer the open pit slope stability conditions of coal in Indonesia are more influenced by the relatively high rainfall, resulting in decreased strength (deterioration) in the rock. Other factors are also considered in the stability curve is the change in dimensions, the orientation of the field discontinuities and shear strength characteristics of rocks. However, these curves have not been able to explain the failure failure probability (FP) slope due to the variation in the factors to be input parameters. The method used in determining the FP value of slope is a point estimate method (PEM).
The results showed that FP values of the stability curve of 10.2% is more pessimistic than the curve Hoek & Bray (0.1%) and Bishop's slice method (0.4%). These results provide an indication that the slope stability is not just rely on the safety factor (SF), but should also look at the failure probability (FP).