Finite-Horizon Bisimulation Minimisation for Probabilistic Systems
- Cite this paper as:
- Kamaleson N., Parker D., Rowe J.E. (2016) Finite-Horizon Bisimulation Minimisation for Probabilistic Systems. In: Bošnački D., Wijs A. (eds) Model Checking Software. SPIN 2016. Lecture Notes in Computer Science, vol 9641. Springer, Cham
We present model reduction techniques to improve the efficiency and scalability of verifying probabilistic systems over a finite time horizon. We propose a finite-horizon variant of probabilistic bisimulation for discrete-time Markov chains, which preserves a bounded fragment of the temporal logic PCTL. In addition to a standard partition-refinement based minimisation algorithm, we present on-the-fly finite-horizon minimisation techniques, which are based on a backwards traversal of the Markov chain, directly from a high-level model description. We investigate both symbolic and explicit-state implementations, using SMT solvers and hash functions, respectively, and implement them in the PRISM model checker. We show that finite-horizon reduction can provide significant reductions in model size, in some cases outperforming PRISM’s existing efficient implementations of probabilistic verification.