PRISM-games is a new extension of PRISM for probabilistic model checking of stochastic multi-player games.

Read the tool paper or visit the website for more information.

PRISM is a probabilistic model checker, a tool for formal modelling and analysis of systems that exhibit random or probabilistic behaviour. It has been used to analyse systems from many different application domains, including communication and multimedia protocols, randomised distributed algorithms, security protocols, biological systems and many others.

Example PRISM graph PRISM can build and analyse several types of probabilistic models:

  • discrete-time Markov chains (DTMCs)
  • continuous-time Markov chains (CTMCs)
  • Markov decision processes (MDPs)
  • probabilistic automata (PAs)
  • probabilistic timed automata (PTAs)
plus extensions of these models with costs and rewards.

Models are described using the PRISM language, a simple, state-based language. PRISM provides support for automated analysis of a wide range of quantitative properties of these models, e.g. "what is the probability of a failure causing the system to shut down within 4 hours?", "what is the worst-case probability of the protocol terminating in error, over all possible initial configurations?", "what is the expected size of the message queue after 30 minutes?", or "what is the worst-case expected time taken for the algorithm to terminate?". The property specification language incorporates the temporal logics PCTL, CSL, LTL and PCTL*, as well as extensions for quantitative specifications and costs/rewards.

PRISM incorporates state-of-the art symbolic data structures and algorithms, based on BDDs (Binary Decision Diagrams) and MTBDDs (Multi-Terminal Binary Decision Diagrams) [KNP04b, Par02]. It also includes a discrete-event simulation engine, providing support for approximate/statistical model checking, and implementations of various different analysis techniques, such as quantitative abstraction refinement and symmetry reduction.

PRISM is free and open source, released under the GNU General Public License (GPL).

To cite PRISM, please use the most recent tool paper, from CAV'11:

Latest News

September 2015: Dave Parker will give a lecture on "Probabilistic Model Checking and Controller Synthesis" at the 2nd AVACS Autumn School on 1 October. See here for resources.
July 2015: A beta release of PRISM version 4.3 is now available. New features include external LTL-to-automata converters and various new model checking algorithms. Details here.
June 2015: PRISM now supports the HOA (Hanoi Omega Automata) format. This allows external LTL-to-automaton converters to be used. More details in this CAV'15 paper.
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