Functional safety is not related to a specific technology. The term is part of the overall safety of a system or piece of equipment that depends on the system or equipment operating correctly in response to its inputs, including the safe management of likely operator errors, hardware and software failures and environmental changes.
The objective of functional safety is freedom from unacceptable risk of physical injury or of damage to the health of people either directly or indirectly by the proper implementation of one or more automatic protection functions.
A safety system (often called safety-related system) consists of one of more safety functions.
Functional safety can be thought of as end-to-end in scope because it has to treat the function of a component or subsystem as part of the function of the entire automatic protection function of any system.
In other words, while functional safety standards focus on electrical, electronic, and programmable systems (E/E/PS), the end-to-end scope means that in practice functional safety methods have to extend to the non-E/E/PS parts of the system that the E/E/PS actuators, valves, motor controls or monitors.
In technical systems, there are considerable risks, including:
- Mechanical risks
- Chemical risks
- Electrical risks
- Explosion risks
Functional safety sees to it that a system, a piece of apparatus or machine is safe in that the risks presented by or to it are acceptably low.
Functional safety relies on active systems such as the detection of smoke by sensors and the ensuing intelligent activation of a fire suppression system. Or, another example, the activation of a level switch in a tank containing a flammable liquid, when a potentially dangerous level has been reached, which causes a valve to be closed to prevent further liquid entering the tank and thereby preventing the liquid in the tank from overflowing.
Safety achieved by measures that rely on passive systems is not functional safety.
Functional safety is a technically challenging field. Certifications should be done by independent organizations with experience and strong technical depth (electronics, programmable electronics, mechanical, and probabilistic analysis).
Functional safety certification is performed by accredited Certification Bodies (CB). Accreditation is awarded to a CB organization by an Accreditation Body (AB). In most countries there is one AB. In the United States, the American National Standards Institute (ANSI) is the AB for functional safety accreditation.
Want to know more about functional safety? Tonex offers several Functional Safety courses.
Additionally, Tonex offers nearly 400 classes, seminars and workshops in close to four dozen categories of systems engineering training.
For more information, questions, comments, contact us.