industrial automation and control system

An industrial automation and control system (IACS) is the integrated set of hardware, software, networks, and supporting infrastructure used to monitor, control, and automate industrial processes. It typically spans from field devices in the plant to supervisory and sometimes enterprise interfaces, and is treated as a system from both operational and cybersecurity perspectives.

Core characteristics

An industrial automation and control system commonly includes:

• Field instrumentation, sensors, and actuators connected to the process or equipment
• Programmable logic controllers (PLCs), remote terminal units (RTUs), and other controllers that execute control logic
• Supervisory systems such as SCADA servers, DCS workstations, and historians
• Human-machine interfaces (HMIs) and operator stations
• Industrial communication networks and protocols (for example, fieldbuses, industrial Ethernet)
• Supporting servers, gateways, and sometimes application software that link OT systems with IT or MES/ERP

In manufacturing, the IACS is what runs production lines, utilities, packaging systems, and other automated operations, often in continuous coordination with quality systems and higher-level planning or execution systems.

Scope and boundaries

The term usually refers to the operational technology (OT) environment responsible for real-time or near real-time control. It focuses on:

• Reliable process control and interlocks
• Acquisition and transmission of process and equipment data
• Execution of automation logic, recipes, and sequences

It typically excludes purely business IT systems such as email, office productivity tools, and non-industrial enterprise applications, even though those may connect to the IACS through defined interfaces.

Operational use in regulated manufacturing

In regulated or high-consequence manufacturing environments, the IACS is a central system of record for:

• Capturing process parameters and setpoints used to demonstrate control of critical operations
• Executing automated steps that must align with validated processes or documented work instructions
• Exchanging data with MES, quality systems, or batch/recipe management systems for traceability and review

From a security and reliability standpoint, organizations treat the IACS as a distinct system, often with its own lifecycle management, change control, and risk assessment processes.

Relation to IEC 62443 and cybersecurity

Within the IEC 62443 series, industrial automation and control systems are the primary focus of security requirements and models. The standard defines IACS as the collection of systems used for industrial automation, including control, monitoring, and related support systems.

For example:

• IEC 62443-3-3 addresses security requirements at the IACS (system) level, considering the deployed architecture, zones, and conduits.
• IEC 62443-4-2 addresses technical security requirements for components that make up an IACS, such as PLCs, HMIs, gateways, and software.

In practice, security levels and requirements are often defined for the IACS as a whole, then allocated down to individual components during design, procurement, and integration.

Common confusion

• IACS vs. SCADA/DCS: SCADA and DCS are specific types of control architectures or systems. An IACS may include SCADA, DCS, or both, as well as other components like stand-alone PLC cells.
• IACS vs. OT: OT (operational technology) is a broader category that covers all industrial control and field systems. An IACS is usually a defined subset of OT, representing a particular integrated control system or automation domain.
• IACS vs. MES: MES manages production execution and information flow above the control layer. The IACS interfaces with MES but is focused on direct control and monitoring of equipment and processes.