What we have here is a pictorial diagram depicting the standard symbols used in fault tree analysis or FTA. The diagram is divided into two sections- Events and Gates. The Events section displays symbols such as Top Event, Intermediate Event, Basic Event, Underdeveloped Event, Transfer In, Transfer Out, Conditional Event and House Event (External Event). The Gates section exhibits symbols such as And Gate, Priority and Gate, Or Gate, Xor Gate, Gate and Inhibit Gate. Each of these symbols are in the shape of some or the other geometric figure. Fault Tree Analysis is an investigation to understand how a top fault or a failure event can be resolved into its causes. The Gates in a FTA are logic symbols that interlink contributory events and conditions. Fault Tree Analysis are mainly utilized to understand the logic leading to the top event or undesired state.
