A working definition
Industrial automation is the use of control systems and equipment to operate machinery and processes with reduced direct human effort. The controls sense conditions, apply programmed logic and drive equipment, while people supervise, set goals and handle exceptions. The term covers a wide spread, from a single machine that stamps parts to a whole plant that treats water.
Automation is not the same as robotics, although robots are one kind of automated equipment. It is also not the same as simple mechanization, such as a hand-cranked device. The defining feature is that a control system makes decisions based on measured conditions.
Main components
A typical system combines several families of equipment.
- Sensors and instruments detect presence, position, speed, temperature, pressure, flow, level and other conditions.
- Controllers run the logic. Programmable logic controllers are widespread, and other controllers handle process loops or coordinated motion.
- Actuators produce action: motors, valves, cylinders, heaters and pumps, often through starters or drives.
- Operator interfaces let people view and command the system.
- Supervisory and data software collects information, shows trends and raises alarms.
- Networks connect everything, from simple wiring to digital communication links.
- Safety systems protect people and equipment, normally designed to operate independently of ordinary control.
Details on each can be found in the sibling articles on control system hardware and process variables.
Levels of an automation system
A common way to organize all of this is to describe levels, from the process up to the business.
- Field level. Sensors, actuators, motors and valves directly on the process.
- Control level. Controllers executing logic and loops.
- Supervisory level. Operator displays and data collection, often described as SCADA systems.
- Operations level. Software for scheduling, quality records, tracking and maintenance. This level is sometimes called manufacturing operations management.
- Enterprise level. Business systems such as planning, ordering and finance.
Real facilities do not always match this layered picture. Newer designs let data move more freely between levels, and some functions overlap. Still, the model gives useful vocabulary for deciding where a given device belongs.
Types of automation
It is common to separate automation by how flexible it is.
- Fixed automation is built for one product or sequence. It tends to be efficient at high volume but hard to change.
- Programmable automation can be reconfigured for different products by changing the program or setup, as in batch production.
- Flexible automation can switch between variants with little downtime, often using programmable machines.
A separate distinction, between discrete and process work, concerns the product. Counted items belong to discrete manufacturing, while flowing materials belong to process industries. Continuous process control and batch process example describe how the latter looks in practice.
Common uses
Automation turns up in many kinds of operations:
- assembly, machining and packaging lines;
- material handling, including conveyors and warehouse systems;
- chemical, food, water and energy processes;
- utilities such as pumping, heating and ventilation;
- inspection and testing, where sensors or cameras check quality;
- monitoring of equipment health.
Each sector emphasizes different parts. For instance, a bottling line leans on sequencing and counting, while a treatment plant leans on measurements and feedback loops. Sector-specific discussion belongs in articles such as water treatment automation and food processing automation.
Potential benefits and tradeoffs
Plants usually pursue automation for consistency, reduced repetitive manual work, better records, and the ability to run equipment more safely or more continuously. These benefits are not automatic. Costs include design, equipment, installation, training and ongoing maintenance, and results depend on how well the system is chosen and looked after. A badly specified system can be harder to run than the manual process it replaced. The tradeoffs around money are the subject of automation budgeting.
Maintenance and security
Automated equipment needs care. Sensors drift, contacts wear, and software and settings must be managed. Connected systems also bring cybersecurity concerns, as network access to a controller is something that should be limited and protected. A growing set of technologies, from IIoT sensors to machine learning role in analysis, builds on the same foundation by adding more data and connectivity.
Safety
Servicing automated equipment can expose people to stored energy, moving parts and electrical hazards. Standard practice includes following the manufacturer’s instructions, using lockout tagout style procedures, and relying on trained and authorized personnel. Local regulations govern many of these requirements. This article is general information, not engineering advice.
A short history pointer
Automation grew from mechanical governors and relay panels to electronic controllers and networked software. The details of that development are covered under automation history, and the current picture is a mix of old and new equipment coexisting in the same plant.