Fault Tree Analysis

Fault Tree Analysis was developed by Bell Telephone laboratories in 1962 for U.S. Air Force and later adopted and extensively used by Boeing Company.
Fault Tree Analysis is in fact a technique by which many events that interact to produce other events can be related using simple logical relationship. This technique follow a top - down structure and represent graphical model of the pathways within a system between basic events that can lead to a foreseeable loss event (or a failure) referred to as the top event.
The logic symbols the most used are AND, OR, etc. – and these symbols are connected by gates. Events that must coexist to cause the top event are described using the AND relationship. Alternate events that can individually cause the top event are described using OR relationship.