Abstract: The present invention provides a system verification system that automatically generates a behavior model modeling the system under test in terms of actions of a test case and a range of expected reactions corresponding to those actions. In this regard, the system verification system obtains a set of actions and individual reactions corresponding to the actions from a plurality of runs of a test case for the system under test, and automatically generates the behavior model representing the system under test in terms of the set of actions and a range of expected reactions each range corresponding one of the actions. The range of expected reactions generalizes and includes all or most of the individual reactions corresponding to said one of the actions.