The paper briefly explains the importance of quantitative procedures of risk analysis in large and medium scale projects for the sustenance of project economic sustainability. Globally, several construction projects are being descoped and tend to close out before attaining the initial project deliverables due to cost and schedule overruns. The quantitative methods can sieve the key factors and forecast the tangible impacts that can lead to schedule or cost variance in a project. It can guide the project stakeholders for timely decision making and mitigate the risks associated to achieve the project goals. Today, the quantitative methods are pivotal to analyze the impacts of Covid-19 crises in Construction industry which are increasingly apparent. Keywords- Project economic sustainability, Risk analysis, Quantitative methods