Glossary · Control theory and process control
Process control
Also known as: Industrial process control
German: Prozessregelung
In industrial automation, process control is the measurement and automatic adjustment of process variables, such as temperature, pressure, flow, level and composition, so that a production process runs at its intended operating point within defined limits.
- Control theory
- Process industry
In one sentence
Process control measures and automatically adjusts variables such as temperature, pressure and flow to keep a production process on target.
Example
In a brewery, process control keeps the wort boiling temperature, the fermentation tank temperatures and the filling line pressure within their specified ranges.
How it applies
- Engineering: Process control combines instrumentation, controllers, actuators and the logic that ties them together. The control strategy, from single loops to Advanced process control (APC), is derived from the process design and its constraints.
- Operation: Operators supervise process control through the HMI of a Distributed control system (DCS) or SCADA system, handle alarms and adjust setpoints.
- Documentation: Key documents are the P&ID, loop lists, control narratives and the operating manual. Keep tag names identical across all of them and the HMI; inconsistent tags are a frequent source of operator error.
Process control vs. statistical process control
Process control adjusts the process continuously and automatically. Statistical process control (SPC) monitors quality data statistically to detect when a process is out of statistical control; it triggers investigation, not an automatic correction.