Automation is basically the delegation of human control function to technical equipment for Increasing Productivity, Increasing Quality, and Reducing Cost Increasing Safety in working conditions.
Plant automation is the complete Automation of the entire process done an industry where there is no human intervention in process, apart from that the only job a human does in monitoring and controlling the whole automation via SCADA or DCS.
Mainly focused on complete modular discrete control consisting of sequential, speed control, packaging & batch control.
As compared to process automation, relatively faster response time is required as a part of factory automation.
Typical actuators, magnetic valves, on/off drives/motors, limit/proximity switches etc. are used along with micro-controllers & modular PLCs as hardware for factory automation.
Continuous monitoring & control including analog & digital measurements.
Computational & calculative controls along with complex control algorithms.
Involves open & closed control loops including PID/Feed forward etc. including the main hardware elements such as sensors (various field sensing devices such as process temp., pressure, flow, level, vibration, switches etc.), final elements (control valves, On-Off valves, SOVs etc.) & Logic Solvers (process controllers such as DCS, PLCs, APCs).
In the absence of process automation, plant operators have to physically monitor performance values and the quality of outputs to determine the best settings on which to run the production equipment. This generally results in operational inefficiency and unsafe operating conditions.
Process automation simplifies this with the help of sensors at thousands of spots around the plant that collect data on temperatures, pressures, flows and so on. The information is stored and analyzed on a computer and the entire plant and each piece of production equipment can be monitored on a large screen in a control room.
In process automation, the computer program uses measurements to show not only how the plant is working but to simulate different operating modes and find the optimal strategy for the plant.