This book aims to present an overview of stochastic system reliability modeling for undergraduate and graduate students, engineers and researchers. It is ideal as a one-semester undergraduate or graduate level text in reliability, applied stochastic processes, stochastic operations research and systems engineering. The topics are divided into two parts: The first part deals with probability theory and stochastic processes, which provide the basic ideas of applied stochastic processes and the second part treats their applications to system reliability modelling. Throughout the later half, Markov renewal processes are applied to formulating stochastic models for system reliability. Since a fairly intermediate level of mathematics is assumed two appendices on Laplace-Stieltjes transforms and signal flow graphs provide much background material. The text is pedagogically sound.