Cost overruns and delays remain quite challenging in large construction and infrastructure projects. These challenges are partly due to the failure to properly identify and quantify second-order effects of risks. Second-order effects of risks are the indirect impact of a risk that can disrupt the overall project schedule and can cause a project to go over budget and run out of schedule. This research highlights the need to better identify
and quantify second-order effects of risks in the design phase of construction and infrastructure projects, where a new methodology is developed that can help in this regard. The research method used, the Double Diamond Design process model, starts with an extensive literature review and semi-structured interviews with experts in the field to clarify the definition of first-order effects and second-order effects of risks and analyse
their current handling. The newly developed method focuses on cascading risk mapping, (dynamic) vulnerability analysis, exposure to risks, probabilistic assessments and Monte Carlo simulations to better predict project outcomes. The new method has been validated by an expert panel, showing that it improves the identification and quantification of risks, although its complexity may require additional training and time
for implementation. This research aims to improve the accuracy of cost estimates and project planning by incorporating second-order effects of risk into these processes. The developed method, while promising in improving the accuracy and clarity of risk management, needs further testing to evaluate its practical efficacy compared to current practices.