FACT : A Probabilistic Model Checker for Formal Verification with Confidence Intervals

We introduce FACT, a probabilistic model checker that computes confidence intervals for the evaluated properties of Markov chains with unknown transition probabilities when observations of these transitions are available. FACT is unaffected by the unquantified estimation errors generated by the use of point probability estimates, a common practice that limits the applicability of quantitative verification. As such, FACT can prevent invalid decisions in the construction and analysis of systems, and extends the applicability of quantitative verification to domains in which unknown estimation errors are unacceptable.