A Practical Guide for Aviation Software and DO-178C

A general definition for safety is the “freedom from those conditions that can cause death, injury, illness, damage to or loss of equipment or property, or environmental harm” [1]. The definition of safety-critical software is more subjective. The Institute of Electrical and Electronic Engineers (IEEE) defines safety-critical software as: “software whose use in a system can result in unacceptable risk. Safety-critical software includes software whose operation or failure to operate can lead to a hazardous state, software intended to recover from hazardous states, and software intended to mitigate the severity of an accident” [2]. The Software Safety Standard published by the U.S. National Aeronautics and Space Administration (NASA) identifies software as safety-critical if at least one of the following criteria is satisfied [3,4]: