| The primary aim of system reliability is the prevention of failures that affect the operational capability of a system. The probability of such failures can be reduced by the following:
• Conservative design—such as ample margins, use of parts and materials with established operating experience, and observing environmental restrictions;
• Use of analysis tools and techniques—particularly failure modes and effects analysis, fault tree analysis and—for electrical components—sneak circuit analysis, followed by correcting the problem areas detected by these;
• Extensive testing—to verify design margins, toleration of environmental extremes, and absence of fatigue and other life-limiting effects;
• Redundancy—to protect against random failures by providing alternative means of accomplishing a required function.
All of these techniques, including their capabilities and limitations, are discussed in this book. In addition, there is a chapter on organizational causes of failure, a subject frequently overlooked in the reliability literature. Failures are attributed to organizational causes when a recognized cause of failure exists and known preventive measures were not installed or used.
This book was written for engineering and management professionals who need a concise, yet comprehensive, introduction to the techniques and practice of system reliability. It uses equations where the clarity of that notation is required, but the mathematics is kept simple and generally does not require calculus. Also, the physical or statistical reasoning for the mathematical model is supplied. Approximations are used where these are customary in typical system reliability practice. References point to more detailed or more advanced treatment of important topics. |