HOW CRITICAL IS YOUR CONTROL-SYSTEM

Basic process control systems are used to regulate the process during normal operation. Safety shutdown system, alarm systems, and other mon itoring systems provide for plant safety. This paper addresses the que stion: ''Is the process control system a critical safety system?'' The answer depends upon its use. Integration of the alarm system and crit ical information functions may make the control system critical to the safety of the process. The criticality of the process control system can be analyzed using process hazards analysis methods. The criticalit y can be reduced by isolating shutdown functions, alarms, and critical monitoring functions from the basic regulatory control functions. And proper choice of equipment and configuration can improve the total re liability of the control system.