Fault Tree Analysis

Fault Tree Analysis (FTA) is a systematic, deductive procedure used to determine the various combinations of hardware and software failures, human errors, and environmental factors that could result in a specific undesirable event, known as the top event. In the context of quantitative risk analysis, FTA helps in identifying potential causes of system failures and assessing the probability of their occurrence. The process begins by defining the top event, which is the primary risk or failure of concern. From there, FTA involves constructing a fault tree—a logical diagram that maps out all possible events contributing to the top event using logical gates like AND and OR. This hierarchical structure illustrates how lower-level failures and conditions combine to cause higher-level system failures. By quantifying the probability of basic events and calculating the likelihood of the top event, FTA provides valuable insights into the most critical risks affecting a project. It enables project managers to focus on high-priority risk areas by identifying minimal cut sets—the smallest combinations of failures that can lead to the top event. FTA supports the development of effective risk mitigation strategies by highlighting where preventive measures or redundancies are most needed. Additionally, it facilitates compliance with safety and reliability standards by providing a documented analysis of potential failure modes and their impacts on project objectives.