Data-Driven Robust Safety Verification for Markov Decision Processes

Abstract: In this paper, we propose a data-driven robust safety verification framework for stochastic dynamical systems modeled as Markov decision processes with time-varying and uncertain transition probabilities. Rather than assuming access to the exact nominal transition kernel, we consider the realistic setting where only samples from multiple system executions are available. These samples may correspond to different transition models inside an ambiguity set around the nominal transition kernel. Using these observations, we construct a unified ambiguity set that captures both inherent run-to-run variability in the transition dynamics and finite-sample statistical uncertainty. This ambiguity set is formalized through a Wasserstein-distance ball around a nominal empirical distribution and naturally induces an interval Markov decision process representation of the underlying system. Within this representation, we introduce a robust safety function that characterizes reach-avoid type probabilistic safety under all transition kernels consistent with the interval Markov decision process. We further derive high-confidence safety guarantees for the true, unknown time-varying system. A numerical example illustrates the applicability and effectiveness of the proposed approach.