Safety Critical Systems

Safety Critical Systems

Electronic systems are used in many safety-critical control applications including aircraft flight control, nuclear reactor operation, industrial machinery and even weapon systems. These systems have proven reliable and safe and in many cases electronic systems have greatly improved both safety and efficiency. The bottom line is that modern practices for development of safety-related electronics reliably produce safe and dependable systems which can be counted on in critical applications.

Properly designed electronic safety-related systems are very different from the desktop and laptop computers many of us use every day. Electronic systems designed for safety are designed from the ground up for reliability. Such systems are almost always based on real-time operating systems; systems which are built to respond on time, every time. Risk assessment, reliability engineering and quality control is a critical part of the entire design process.

The primary international standard for development of safety-critical electronic systems is IEC 61508 "Functional Safety of Electrical/Electronic/Programmable Electronic Safety-related Systems". Similar standards include MIL-STD-882E, used by the military in the United States, and Def Stan 00-56, used by the military in the United Kingdom. Such standards may or may not be directly applicable in certain jurisdictions or to certain projects or operations, but they contain a more-or-less common set of principles for development and use of safety-critical systems which represent standard practice worldwide.

Organizations operating and procuring electronic systems for safety critical applications should ensure that they are acquiring systems from qualified vendors who adhere to standard practices and that the equipment is suitable for their operations and their regulatory environment. It is particularly important to assure that acquired equipment meets an organization's risk acceptance criteria.