ABSTRACT
This chapter presents the concepts of risk and reliability and how they can be considered in engineering planning and design. It explores reliability-based design. The concepts of risk and reliability are defined and illustrated in relation to engineering problems. Reliability-based design and the selection of safety coefficients are explained in detail. The reliability of an engineering component or system is defined as the probability that the system will be in a non-failure state. The reliability of a system at a particular point in time is the probability that it will be in a non-failure state at that time. Engineering systems can be designed to achieve a specified level of reliability due to known hazards, although there are often unexpected hazards that are difficult to quantify. In addition to reliability, resiliency and vulnerability of a system may also be important in planning and design.
