While the complexity of construction projects is increasing, the acceleration of economic, technological, social, and environmental changes challenges managers and policymakers with a strong need to learn and investigate the factors affecting projects. Most of the current problems are unintended side effects of our previous decisions. This study aims to investigate various influencing factors and interactions between them to help construction managers make better decisions. At first, key factors of delay and cost overruns in construction projects were identified through a literature review. Then, a system dynamics approach was developed for the modeling of continuous variables, including casual loop diagrams and stock-and-flow diagrams.