This book is intended to serve a wide variety of users. This updated third edition provides the detailed background necessary to understand how to meet important new safety regulations and reliability engineering topics. Professional control system designers will learn to properly evaluate control system components, various system architectures, how to better communicate with vendors, and how to increase accuracy of life-cycle cost estimates. The book is also an excellent text for college courses due to its detailed explanations, practical presentation, and discussion of the difference between theory and real-world application. It provides a basic foundation of material, including probability, statistics, reliability theory definitions, and basic reliability modeling techniques, as well as advanced topics relevant to safety instrumented and control systems. Each chapter contains exercises to assist the reader in applying the theories presented with their practical implementation.