An evaluation of a system's capacity to withstand unanticipated or unplanned occurrences without suffering harm, loss, or improper operation. A system or procedure must be functionally safe in order to protect people, property, and the environment. Functional Safety combines several reliability-realization techniques with active and passive safety components to accomplish predetermined levels of risk reduction. They are employed for system condition monitoring or hazardous condition identification.
Functional Safety levels may be activated for a number of reasons, including power outages, temperature overshoots, etc. to take the necessary action, such as opening emergency shutdown valves that, in the event of a nuclear disaster, release cooling inert gas into reactor vessels and stop flow in pipes transporting combustible fluids. Automatically accomplishing this requires specialised electronic gear, such as fail-safe circuitry (relays) that are built with fuses and other safety features to enable safer operation without human involvement under problematic operating circumstances.
Once the safety requirements have been established, the system design can proceed. Safety design involves designing the system architecture, selecting appropriate components and subsystems, and implementing safety measures to achieve the required SIL. Safety design may also involve the use of redundancy, fault tolerance, and diagnostic measures to enhance the system's reliability and availability.
Safety verification and validation are critical components of the Functional Safety process. Safety verification involves ensuring that the system design meets the safety requirements, while safety validation involves demonstrating that the system operates correctly under all foreseeable conditions. Safety verification and validation may involve a range of techniques, such as simulation, testing, and analysis.
