Fault Tree Analysis is technique for reliability and safety analysis. It is used in air force for use with the minuteman system. It is mainly used in the field of safety engineering to quantitatively determine the probability of a safety hazard. It is basically composed of logic diagrams that display the state of the system and is constructed using graphical design techniques. It is used in safety engineering and in all major fields of engineering. It is a logical, structured process that help identify potential causes of system failure before the failures actually occur and powerful design tools that can help ensure that product performance objectives. It includes manufacturing equipment, automotive subsystems, aircraft, nuclear power plants, and weapons systems.