Software Engineering, 10th Edition

11.3 Fault-tolerant architectures

Fault tolerance is a runtime approach to dependability in which systems include mechanisms to continue in operation, even after a software or hardware fault has occurred and the system state is erroneous. Fault-tolerance mechanisms detect and correct this erroneous state so that the occurrence of a fault does not lead to a system failure. Fault tolerance is required in systems that are safety or security critical and where the system cannot move to a safe state when an error is detected.

To provide fault tolerance, the system architecture has to be designed to include redundant and diverse hardware and software. Examples of systems that may need fault-tolerant architectures are aircraft systems that must be ...