Safety systems provide protection to the process, physical equipment, or people from harmful situations that may arise during operations. It is a counter action critical in industrial operations in the case of a process goes beyond allowable control parameters.
While this would result in a loss of productivity, it would spare the equipment and people harm. Safety systems are traditionally, designed to be separated from the control systems they protect. However, they frequently share some communications, field devices, alarms, etc.
Copyright: Cybersecurity & Infrastructure Security Agency