It's important to protect all software against the possibility of system failure, but when the software is governing vital safety equipment, that need is even more serious.
Fortunately for developers, the International Electrotechnical Commission's 61508 standard provides a detailed set of guidelines for this process. The standard covers a wide array of safety-related equipment, including medical devices, railway signaling systems, gas burner management and emergency shut-offs.
IEC 61508 uses a number of different gradations to distinguish the four levels of safety standards encompassed within its overall framework, meaning that more extensive amounts of embedded software testing and other protocols are required for more critical systems.
The standard emphasizes active systems for functional safety over passive ones. A smoke detector activating a fire suppression system or a pressure sensor tripping a valve to prevent a tank from overflowing would be examples of such an active approach, according to the IEC, while fire-resistant doors and high-temperature insulation are considered passive systems.
IEC 61508 is intended to function as a stand-alone framework for electronic systems, the group says. It also receives scheduled updates by the IEC's maintenance teams.