Process management systems generally are used to run technical systems. The term was coined in the 1970s when the first proprietary systems for managing refineries and crackers came into being. These systems were both hardware- and software-encapsulated and were tailored to the special demands of the respective applications. Data exchange occurred exclusively within the system.

Until then, the NAMUR level model was the organizational plan for process management technology. The process management system therefore finds itself at the lowest level of the process management level. Communication between the levels is increasingly gaining importance. In this area, the systems also grow closer and closer together. Transitions are fluid. On the production level, an MES should be implemented as a management system.

• Real-time ability. The real-time ability of a system is composed of the punctuality and simultaneousness of the system. Punctuality means the capability of the process computer to react within a defined period of time in the course of a technical process [DIN 44300]. The result here is that the response time of the automation system must be shorter than the actual process time. Simultaneousness means the quasi-parallel processing of numerous computing processes. For example, the regular intervals for an industrial titration process could be measured in seconds, whereas the intervals for a fighter plane would have to be measurable in microseconds. However, both systems are real-time-enabled with respect to the special area of application.
• High availability through redundancy. For complex industrial processes that are automated by process management systems, disruptions or short-term interruptions of workflows cause high failure costs, in the worst case, even danger to people or the environment. In order to increase availability, at least the critical parts of the system must be designed with redundancy. This means that the functions (e.g., field bus, sensor, PLC, etc.) should be taken over by reserve components without interruption in the case of a malfunction.
• Openness and interoperability. Openness means that the external interfaces and system characteristics of the respective manufacturer are disclosed so that it is possible to link any applications from other manufacturers. Interoperability guarantees that different components (e.g., field devices) from different manufacturers can be used together without additional outlay. Both characteristics are the basic conditions for vertical communication in the company.
• Universality of an entire system. Process information that is known at any point in the system must be accessible to every other component at any time without additional outlay.

Principal Structure of a Process Management System

The typical structure of today’s decentralized process management systems.

• Process-oriented component. A process-oriented component is a process computer, usually set up as a programmable logic controller (PLC), on which the functions having a direct effect on the process (e.g., PID regulator) are run. Furthermore, all sensors and actuators are connected to it. This can be done either on a point-to-point network or on a field bus.
• Display and user component. The display and user component creates the interface between the management system and the person running the system. Another term for this is human-machine interface (HMI) or simply process visualization. As well as installation images, there are also views for recipe administration, alarm management, etc.
• Engineering component (EC). The EC or engineering station (ES) allows the system functionality to be configured. This includes configuration of process-based components as well as display and user components.
• System bus. The system bus connects process-oriented components with each other and with the other components of the process management system such as display and user components and EC. This should not be confused with the subordinate field bus for connecting sensors and actuators to the controls. The system bus is always executed redundantly.
• Open operation bus or plant bus. This bus is the open interface of the system to the superimposed systems. The de facto standard for this is Ethernet with the transmission control protocol/Internet protocol (TCP/IP). The execution of this communication medium is not redundant.