Conclusions This paper formally establishes a hierarchy, among the most commonly used types of dependability models, according to their modeling power. Among the combinatorial (non-state-space) model types, we show that fault trees with repeated events are the most powerful in terms of kinds of dependencies among various system components that can be modeled (which is one metric of modeling pow...

The predominant technique for computing the transient distribution of a Continuous Time Markov Chain (CTMC) exploits uniformization, which is known to be stable and efficient for non-stiff to mildly-stiff CTMCs. On stiff CTMCs however, uniformization suffers from severe performance degradation. In this paper, we report on our observations and analysis of an alternative technique using Krylov su...

We present CCMC (Conditional CSL Model Checker), a model checker for continuous-time Markov chains (CTMCs) with respect to properties specified in continuous-time stochastic logic (CSL). Existing CTMC model checkers such as PRISM or MRMC handle only binary CSL until path formulas. CCMC is the first tool that supports algorithms for analyzing multiple until path formulas. Moreover, CCMC supports...

We study the complexity of a class of Markov decision processes and, more generally, stochastic games, called 1-exit Recursive Markov Decision Processes (1-RMDPs) and Simple Stochastic Games (1-RSSGs) with strictly positive rewards. These are a class of finitely presented countable-state zero-sum stochastic games, with total expected reward objective. They subsume standard finite-state MDPs and...

The computation of counterexamples for probabilistic model checking has been an area of active research over the past years. In spite of the achieved theoretical results in this field, there is no freely available tool that allows for the computation and representation of probabilistic counterexamples. We present an open source tool called DiPro that can be used with the PRISM and MRMC probabil...

Conclusions Performability models of multiprocessor systems and their evaluation are presented. Two cases in which hierarchical modeling is applied are examined. 1. Models are developed to analyze the behavior of processor arrays of various sizes in the presence of permanent, transient, intermittent, and near-coincident faults. Models can be generated for typical reconfiguration schemes that co...

In this paper we generalize a method (called regenerative randomization) for the transient solution of continuous time Markov models. The generalized method allows to compute two transient measures (the expected transient reward rate and the expected averaged reward rate) for rewarded continuous time Markov models with a structure covering bounding models which are useful when a complete, exact...