SCADA (Supervisory control and data acquisition) is an industrial control system architecture for process and production management. It based on networks of computers, HMIs (human machine interfaces – graphical touch screens or keyboard operated monitors), which collect data from local programmable logic controllers, PID controllers, sensors and actuators on the process plant. This data is interpreted by software within the SCADA system.

SCADA systems have the ability to adjust machinery settings automatically in response to changing conditions or requirements, thus providing full industrial automation capabilities. They can also be programmed to activate alarms if the process parameters go out of tolerance and even initiate emergency shutdowns if necessary. The inclusion of HMIs allows operators to easily monitor the overall process or any part of it in real time and adjust settings if required.

It also logs all events that occur within the process or on the plant and machinery into a file for archiving, review, analysis, track-and-trace etc. It can interface to Manufacturing Enterprise Systems (MES), business management systems, and other IT networks. SCADA is used in process and manufacturing plants, power generation, refining, telecommunications, transportation, water distribution, etc

One of the advantages of SCADA is that it can be accessed remotely. This means senior managers can monitor production even when not on site, SCADA based information can be supplied to other systems, such as the operating ordering and sales systems. A company can optimise two or more plants against one another, and real time information can be supplied to approved third-party organisations. It also allows operatives to interrogate the system by mobile devices such as tablet computers and smartphones.

Such remote communications are usually enabled using wireless technologies and as a result the current generation SCADA technology has cyber security capabilities built into it. Further, while traditionally SCADA software has been hosted on an on-site computer, web-based SCADA is becoming popular particularly for smaller applications.