# Fault tree analysis Fault tree analysis is a top-down [[Deductive_reasoning|deductive]] method that decomposes an undesired top event into combinations of basic faults via [[Boolean_algebra|Boolean]] logic gates (AND, OR, etc.). Quantitative probabilistic evaluation of minimal cut sets supports risk assessment, diagnostics, and design improvement in safety-critical systems. It is a core tool of [[Reliability_engineering|reliability engineering]]. ## Reveal %%REVEAL:mermaid%% %%REVEAL:svg%% --- *Concept aligned with [Wikipedia](https://en.wikipedia.org/wiki/Fault_tree_analysis); adapted text, where present, is licensed [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/).* ## Overview Born at [[Bell_Labs|Bell Labs]] for the Minuteman program and matured by [[Boeing|Boeing]], [[NASA|NASA]], and the nuclear industry, the method quantifies gate logic with [[Probability_theory|probability theory]], [[Statistics|statistics]], the [[Algebra_of_sets|algebra of sets]], and [[Independence_(probability_theory)|independence]] assumptions — extending to the [[Markov_chain|Markov chain]] when order and repair matter. Its inductive complements are [[Failure_mode_and_effects_analysis|FMEA]] and [[Event_tree_analysis|event tree analysis]] inside a full [[Hazard_analysis|hazard analysis]]. Regulators made it doctrine: the [[Federal_Aviation_Administration|FAA]] and [[ARP4761|ARP4761]] for [[Aircraft_systems|aircraft systems]] and [[Airworthiness|airworthiness]], [[System_safety|system-safety]] programs across [[Aerospace|aerospace]], and post-accident analysis from the [[Nuclear_reactor|nuclear reactor]] fleet to the [[International_Space_Station|International Space Station]] — deductive trees keeping [[Complex_system|complex systems]] honest about their [[Failure_rate|failure rates]]. ## Wikipedia : Wikitube **Strict pair:** [Wikipedia](https://en.wikipedia.org/wiki/Fault_tree_analysis) : [Wikitube](https://en.wikitube.io/wiki/Fault_tree_analysis) ## Previous hub tags Hubs: `Systems`. Portals: [[PORTAL_Systems]], [[PORTAL_Fault_tree_analysis]].