Reliability evaluation of fly-by-wire computer systems
Abstract Computer systems that are used for critical applications are designed to tolerate both software and hardware faults by executing multiple software versions on redundant hardware. This integrated approach to fault tolerance is difficult to analyze using existing techniques that consider hardware and software separately. In this article, a combination of fault trees and Markov models are used to provide an integrated analysis of a portion of the flight control systems used on the Airbus A310 and A320 aircraft. The goal of the analysis is to determine the reliability of each system, that is, the time-dependent probability of producing an acceptable result. An unacceptable output can be the result of hardware or software faults that are not tolerated by the level of redundancy provided.