ABSTRACT
This chapter presents the Reliability Block Diagrams (RBDs). First, however, reliability and availability modeling methods are classified. Next, the RBD compositions are described. It presents a classification of models used for availability and reliability evaluation. Combinatorial models capture conditions that make a system fail (or to be working) regarding structural relationships between the system components. Although RBD was initially proposed as a model for calculating reliability, it can be used for computing other dependability metrics, such as availability and maintainability. Series and parallel structures can be combined to form more complex system configurations. Decomposition is very convenient when defining the structure, reliability, and availability functions of systems. A common cause failure can be internal or external to the system and can act simultaneously on significant (if not all) components of a system. The reliability importance may also be presented in relation to the most reliable component.
