Fault tree analysis - common misconceptions

Fault tree analysis is a technique commonly used to assess the system failure likelihood or frequency in terms of failure or repair parameters of its components. It is a mathematical modelling method used to assess engineering systems in a very diverse range of industries. It has become apparent during my involvement in systems reliability quantification projects that there are several misconceptions involving the use of the method. these misconceptions range through all aspects of the fault tree method from the construction of the failure logic diagram through qualitative analysis and quantitive analysis. This paper deals with some of these misconceptions and the problems that can result.