Closely related to the SCADA system is the distributed control system. The differences between a SCADA system and a DCS are very small and the two have become almost indistinguishable over time. Traditionally, though SCADA systems were used for automation tasks that cover a larger geographical area, meaning that parts of the SCADA system are located in separate buildings or facilities as where a DCS is more often confined to a single plant of facility. A DCS is often a large-scale, highly engineered system with a very specific task. It uses a centralized supervisory unit that can control thousands of I/O points. The system is built to last with redundancy applied to all levels of the installation, from redundant networks and network interface attached to redundant server sets to redundant controllers and sensors, all with creating a rigid and solid automation platform in mind.

DCS systems are most commonly found in water management systems, paper and pulp mills, sugar refinery plants, and so on: