Discrete event systems: definitions and examples. Untimed models of discrete event systems: state automata. Timed models of discrete event systems: clock structures, event timing dynamics, timed automata. Review of stochastic processes: definitions, stationary and ergodic processes, Markov and semi-Markov processes. Counting processes: Poisson processes, memoryless property and superposition of Poisson processes. Stochastic timed automata: stochastic clock structures, generalised semi-Markov processes, automata with Poisson clock structure. Discrete-time Markov chains: Chapman-Kolmogorov equations, transition probability matrix, classification of states, stationary distributions and limiting probabilities. Continuous-time Markov chains: Kolmogorov equations, transition rate matrix, classification of states, stationary distributions and limiting probabilities, birth-death chains. Queueing theory: specification of queueing models, Kendall's notation, Lindley equation, Little's law, Markovian queueing systems and networks, PASTA property.