With the increasing of the cost and complexity of products,Failure Modes and Effects Analysis(FMEA) are becoming an indispensable part of the design process of complex systems.However,it isn't effective for complex system due to the qualititative reasoning maily by experiences,which is overloaded with details.It is difficult to ensure the fault effect of each fault modes.In this paper,based on the functional role model theory,the reasoning rule and the technique of FMEA,which are facing to Built in Test(BIT),are developed.The process of fault analysis is illustrated by the Fuel metering System of jet plane engine.The results of research show that the fuctional role model theory can be more efficient and effective in the FMEA.