 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.