An efficient state space generation for the analysis of real-time systems

State explosion is a well-known problem that impedes analysis and testing b ased on state-space exploration. This problem is particularly serious in re al-time systems because unbounded time values cause the state space to be i nfinite even for simple systems. in this paper, we present an algorithm tha t produces a compact representation of the reachable state space of a real- time system. The algorithm yields a small state space, but still retains en ough information for analysis. To avoid the state explosion which can be ca used by simply adding time values to states, our algorithm uses history equ ivalence and transition bisimulation to collapse states into equivalent cla sses. Through history equivalence, states are merged into an equivalence cl ass with the same untimed executions up to the states. Using transition bis imulation, the states that have the same future behaviors are further colla psed. The resultant state space is finite and can be used to analyze real-t ime properties. To show the effectiveness of our algorithm, we have impleme nted the algorithm and have analyzed several example applications.