Probabilities of Qualitative Behaviors for Dependability Analysis of a Fault-Tolerance Model

The quantitative aspects of model specifications are often only partially known. Thus there is a need for ways to analyze models whose quantitative specifications are incomplete. One important goal for model analysis is finding the probabilities of the different qualitatively distinct behaviors a model can exhibit. We show how a model with partial quantitative specifications may be analyzed to bound the probabilities of its behaviors. Some of these partial quantitative specifications may be characterized by intervals and others by probability distributions, making the technique quite flexible in its ability to use whatever quantitative information is available. The technique takes knowledge in the form of a structural model with partial quantitative specifications. This model is used to automatically construct behaviors by simulating it. These behaviors together with the given partial quantitative information are then analyzed probabilistically by a modification of the..