AbstractThe reliability and availability of a dynamic route guidance system (RGS) using a fault tree is analyzed and a mathematical model of its failute is presented. The proper functioning of the system is dependent on many components including navigation system, surveillance system, communication system, hardware and software. Failure on the part of these elements may affect the reliability of the system. This study presents the application of fault tree analysis to model failure mechanisms of the system. Qualitative and quantitative analyses are performed on the fault tree. The analysis includes the determination of cut sets, system unavailability, system reliability, and importance of subsystem components. Graphs are presented for illustrating the availability and reliability of the subsystems of RGS. The reliability and availability of RGS can be determined from these graphs.