State tree analysis of FOG based on drift brownian motion

The binary state is the fundamental assumption to the traditional FTA. Hence, the traditional FTA gives only the binary logical analysis of product catastrophic failures. However, performance of Fiber Optical Gyroscope (FOG) will degrade with the time and it is able to perform its task with partial performance. To overcome this problem, multistate reliability analysis is presented. However, multistate reliability analysis is conducted by assuming that products have a number of discrete states. In most cases, product physical parameters are continuous real variables. Consequently, we combine the state analysis to FTA, and construct the state tree of FOG. By assuming that the state of SLD can be depicted by the drift Brownian Motion (DBM), we calculate the top event probability. Finally, we contrast the two top event probabilities of DBM and the model in, respectively.