Computer control of decentralized process systems

Abstract

All processes, such as oil refineries, chemical plants, steel mills, etc. are distributed in the sense that the process equipment, measurement sensors and final control elements are distributed over a significant geographical area. Historically, process control systems have changed from the original, fully-distributed, manual systems, to centralized control rooms, to what are now called distributed computer control systems. This paper presents a board overview of process-computer systems from the point of view of the user, or process engineer. The major conclusions are that process computer systems are evolving from first-level process control functions to higher-level plant supervisory and management functions; that it is time to change from bottom-up development to top-down design; that process computer systems are becoming less of a separate specialty, and more of an inter-disciplinary area; and that there is a real need for an organized, international group of process and computer-oriented people to develop a high-level functional specification and statement of requirements for plant-wide process control and management systems. The design and implementation of such systems should be done by computer specialists, not process personnel. Interdisciplinary cooperation will lead to better process systems.