ABSTRACT
Once a candidate design is available, a more accurate failure analysis is needed, and this is created during the detailed design cycle, although the Markovian technique may be adequate for the initial design cycle. This chapter investigates the use of fault tree analysis and describes a conventional Boolean fault tree. It examines the more powerful and flexible technique of Bayesian fault tree analysis. Any failure analysis of a system needs as input the failure rates of the individual components of the system, and the question arises of how to estimate the failure rate of a software component. In addition to noisy OR, there are other noisy conjunctions and operators. Noisy AND is constructed in a manner analogous with noisy OR in that all inputs must be true to a particular degree for the output to be true, and even then there is a possibility that the output is not true.
