Textbook in PDF format System dependability is a complex task to grasp and analyze since it encompasses reliability, maintainability, availability, failure mode analysis and feared events. For operational safety analyses, reliability is a quantitative basis for the other disciplines of maintainability, availability and safety. Reliability metrics such as failure rate or MTBF are often misused as they are only valid for low-maintenance applications, and wrongly for others, as MTBF is only relevant for availability. In addition, in operational safety, many equations do not have explicit solutions, and Monte Carlo simulations are a little-used way of obtaining and/or confirming the solution obtained by numerical methods