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This paper presents new algorithms and accompanying tool support for analyzing interactive Markov chains (IMCs), a stochastic timed 1 1 2 -player game in which delays are exponentially distributed. IMCs are compositional and act as semantic model for engineering formalisms such as AADL and dynamic fault trees. We provide algorithms for determining the(More)
Costs and rewards are important ingredients for many types of systems, modelling critical aspects like energy consumption, task completion, repair costs, and memory usage. This paper introduces Markov reward automata, an extension of Markov automata that allows the modelling of systems incorporating rewards (or costs) in addition to nondeterminism, discrete(More)
Effective risk management is a key to ensure that our nuclear power plants, medical equipment, and power grids are dependable; and it is often required by law. Fault Tree Analysis (FTA) is a widely used methodology here, computing important dependability measures like system reliability. This paper presents DFTCalc, a powerful tool for FTA, providing (1)(More)
Markov automata (MA) constitute an expressive continuoustime compositional modelling formalism. They appear as semantic backbones for engineering frameworks including dynamic fault trees, Generalised Stochastic Petri Nets, and AADL. Their expressive power has thus far precluded them from effective analysis by probabilistic (and statistical) model checkers,(More)
RAMS (Reliability, Availability, Maintenance, Safety) requirements are utmost important for safety-critical systems like railroad infrastructure and signaling systems, and often imposed by law or other government regulations. Fault tree analysis (FTA, for short) is a widely applied industry standard for RAMS analysis [1, 2], and is often one of the(More)
The current trend in infrastructural asset management is towards risk-based (a.k.a. reliability centered) maintenance, promising better performance at lower cost. By maintaining crucial components more intensively than less important ones, dependability increases while costs decrease. This requires good insight into the effect of maintenance on the(More)
The intricacy of socio-technical systems requires a careful planning and utilisation of security resources to ensure uninterrupted, secure and reliable services. Even though many studies have been conducted to understand and model the behaviour of a potential attacker, the detection of crucial security vulnerabilities in such a system still provides a(More)
Effective risk management is a key to ensure that vital assets like our nuclear power plants, medical equipment, and power grids are dependable. Also, risk management is often required by law. Fault Tree Analysis (FTA) is a widely used methodology here, computing important dependability measures like system reliability and availability. This paper presents(More)
Markov automata (MAs) extend labelled transition systems with random de-<lb>lays and probabilistic branching. Action-labelled transitions are instantaneous and yield<lb>a distribution over states, whereas timed transitions impose a random delay governed by<lb>an exponential distribution. MAs are thus a nondeterministic variation of continuous-time<lb>Markov(More)
Fault tree analysis is a widespread industry standard for assessing system reliability. Standard (static) fault trees model the failure behaviour of systems in dependence of their component failures. To overcome their limited expressive power, common dependability patterns, such as spare management, functional dependencies, and sequencing are considered. A(More)