Fault tree analysis

Summary

Fault tree analysis (FTA) is a type of failure analysis in which an undesired state of a system is examined. This analysis method is mainly used in safety engineering and reliability engineering to understand how systems can fail, to identify the best ways to reduce risk and to determine (or get a feeling for) event rates of a safety accident or a particular system level (functional) failure. FTA is used in the aerospace, nuclear power, chemical and process, pharmaceutical, petrochemical and other high-hazard industries; but is also used in fields as diverse as risk factor identification relating to social service system failure. FTA is also used in software engineering for debugging purposes and is closely related to cause-elimination technique used to detect bugs. In aerospace, the more general term "system failure condition" is used for the "undesired state" / top event of the fault tree. These conditions are classified by the severity of their effects. The most severe conditions require the most extensive fault tree analysis. These system failure conditions and their classification are often previously determined in the functional hazard analysis. Fault tree analysis can be used to: understand the logic leading to the top event / undesired state. show compliance with the (input) system safety / reliability requirements. prioritize the contributors leading to the top event- creating the critical equipment/parts/events lists for different importance measures monitor and control the safety performance of the complex system (e.g., is a particular aircraft safe to fly when fuel valve x malfunctions? For how long is it allowed to fly with the valve malfunction?). minimize and optimize resources. assist in designing a system. The FTA can be used as a design tool that helps to create (output / lower level) requirements. function as a diagnostic tool to identify and correct causes of the top event. It can help with the creation of diagnostic manuals / processes. Fault tree analysis (FTA) was originally developed in 1962 at Bell Laboratories by H.