1. A method of conversion of fault trees to Bayesian networks for assisting in system reliability, failure analysis and diagnostics comprising the steps of: creating a structure of a Bayesian network using information from a fault tree; creating parameters of the Bayesian network using information from the fault tree; obtaining information about observation nodes for the Bayesian network from a list of observations that augments information contained in the fault tree; and inserting the observation nodes into the Bayesian network.