"Top-Down and Bottom-Up" risk analysis is one of many effective tools to evaluate and control project schedules and cost estimate uncertainty, but it's effectiveness is directly linked to mitigation measures to optimize the project and realize true project improvement. To this end, risk analysis is often used in parallel with brainstorming techniques and incorporated into value engineering studies as a means to evaluate mitigation alternatives and selection of specific actions to optimize the return on investment (ROI) of various possible mitigation strategies. Owners have the choice to accept, share the risk with others, i.e. contractors, or mitigate. Each of these have secondary risks which may require follow-on analysis to identify the preferred course of action.
The following YouTube link by David Hamilton, PE, CVS-Life, CCP details some of the current trends in risk analysis and the benefits being realized on major civil engineering projects.