Project cost contingency has been studied in several scholarly communities interested in project management. Numerous references have discussed its methods of estimating and modelling in the preliminary planning phase of the project while concluding version zero of the project management plan. In such a phase, project potential risk is assessed quantitatively to calculate a monetary allowance to handle project risk effects in the event that they occur and become a real issue. However, for a project management environment, there are not enough familiar practices that discuss or present a comprehensive methodology to simply and robustly manage it throughout the project execution phase. Also, the responsive decisions that should be taken to deal with its status, whether it turns out to be adequately estimated or not, have not been discussed or studied enough before.This paper is aiming to present a simple and robust method to help project managers perform such a function, depending on the widely used earned value method (EVM) to measure performance throughout execution at selected points of accomplished control account. Depending on embedding an index that expresses the project risk within the performance measurement process The concept of risk performance index (RPI) as a reflection of the relationship between pre-assessed quantitative risk during the planning phase and real world risk that has become an issue is similar to the widely used concept of monitoring project performance by earned value, which takes into account cost performance index. The cost performance index (CPI) is a ratio of planned to actual costs, while the schedule performance index (SPI) is a ratio of two time-oriented values. This study will present a proposal for a risk performance index (RPI) to express the impact of project risk on project performance and to better manage project risk, which will be a ratio of two risks (preassessed during the project planning phase and actual occurring risks). The contingency budget management process was investigated. This was done via an integrated analysis of available standards provided by internationally recognized project management associations (PMI, IPMA, PMA, etc.) and the pertinent scholarly literature, in particular an analysis of literature on contingency management, which was developed based on the idea that it is a consistent and conducive methodology to deal with this topic. All past proposed models depend on original project cost estimation, expert judgment, or both for risk analysis. So the validity of these models depends on the accuracy of estimates and unbiased opinions from experts. Tremendous effort is required to collect pertinent and correct information for model inputs, and when the risk environment changes, the process must be restarted to obtain the correct information.