Safety criteria and model for mission-critical embedded software systems

A set of safety criteria for mission-critical embedded process control software systems is suggested, and a preliminary mathematical model of a safe system based on the criteria is described. The criteria are properties that, when possessed by an embedded process control software system, will support a safety requirement. The mathematical model uses a finite state machine representation to formalize the definitions and to enable one to prove safety properties mathematically. Some of the criteria presented are derived from specific requirements presently found in a variety of mission-critical process control embedded software systems. Others are derived from analogous requirements found in the computer security field