CPS Real-Time, CPS Formal Methods
Date of this Version
Lecture Notes in Computer Science: Hybrid Systems: Computation and Control
Model checking is a popular algorithmic verification technique for checking temporal requirements of mathematical models of systems. In this paper, we consider the problem of verifying bounded reachability properties of stochastic real-time systems modeled as generalized semi-Markov processes (GSMP). While GSMPs is a rich model for stochastic systems widely used in performance evaluation, existing model checking algorithms are applicable only to subclasses such as discrete-time or continuous-time Markov chains. The main contribution of the paper is an algorithm to compute the probability that a given GSMP satisfies a property of the form “can the system reach a target before time T within k discrete events, while staying within a set of safe states”. For this, we show that the probability density function for the remaining firing times of different events in a GSMP after k discrete events can be effectively partitioned into finitely many regions and represented by exponentials and polynomials. We report on illustrative examples and their analysis using our techniques.
The original publication is available at www.springerlink.com
Rajeev Alur and Mikhail Bernadsky, "Bounded Model Checking of GSMP Models of Stochastic Real-Time Systems", Lecture Notes in Computer Science: Hybrid Systems: Computation and Control 3927, 19-33. January 2006. http://dx.doi.org/10.1007/11730637_5
Date Posted: 25 June 2012