What Is Industrial Automation? A Guide for Engineers and Manufacturing Leaders
This guide explains industrial automation for UK engineering professionals and manufacturing leaders, covering the core technologies, architectures and standards that underpin modern automated systems. It explores PLCs, SCADA, industrial networking protocols and the standards that govern safe and interoperable deployments. Whether you are deepening your technical knowledge or building an automation team, this article provides a practical foundation.
What Is Industrial Automation? A Guide for Engineers and Manufacturing Leaders
Industrial automation is the use of control systems, software and instrumentation to operate industrial processes with minimal human intervention. It spans a broad range of technologies: from a single programmable logic controller managing a conveyor line, through to fully integrated, plant-wide systems coordinating hundreds of field devices, robots and enterprise software platforms. For UK engineering professionals and manufacturing leaders, understanding the layers of an automation architecture, the standards that govern it and the skills required to deliver it has become increasingly important as factories modernise and digital transformation programmes accelerate across sectors including food and beverage, pharmaceuticals, oil and gas, water treatment and advanced manufacturing.
The Core Layers of an Industrial Automation Architecture
Industrial automation systems are typically described using the ISA-95 model, which organises plant operations into a hierarchy of functional levels. Understanding these layers helps engineers and managers communicate clearly about where a given technology sits and what it needs to interface with.
Level 0 and Level 1: Field Devices and Basic Control
At the lowest levels sit the physical devices that interact directly with the process: sensors, actuators, drives, valves and transmitters. Signals from these devices are wired to, or communicated digitally with, the control layer above. Instrumentation at this level commonly uses HART (Highway Addressable Remote Transducer) for smart field device communication, allowing diagnostics and configuration to be passed over the same two-wire loop as the analogue signal.
Level 2: Supervisory Control and PLCs
Programmable Logic Controllers (PLCs) and Distributed Control Systems (DCSs) sit at Level 2, executing the real-time control logic that governs the process. The major PLC platforms in use across UK industry include:
- Siemens S7-1500 and S7-300/400 series, programmed via TIA Portal. For a deeper look at TIA Portal specifically, see Siemens TIA Portal Explained: Getting Started with Siemens PLC Programming.
- Allen-Bradley ControlLogix and CompactLogix from Rockwell Automation, using Studio 5000 Logix Designer.
- Beckhoff CX series, which runs TwinCAT on standard PC hardware, blurring the line between traditional PLC and software PLC.
- Schneider Electric Modicon M340 and M580, programmed via EcoStruxure Control Expert.
- Mitsubishi MELSEC iQ-R and iQ-F series, widely used in automotive and material handling.
- ABB AC500, common in energy, process and infrastructure applications.
All modern PLCs support programming in one or more languages defined by IEC 61131-3: Ladder Diagram (LD), Structured Text (ST), Function Block Diagram (FBD), Instruction List (IL) and Sequential Function Chart (SFC). Structured Text has become the preferred language for complex logic and data manipulation, while Ladder remains dominant for discrete control due to its readability for maintenance engineers.
Level 3: SCADA, MES and HMI
Supervisory Control and Data Acquisition (SCADA) systems provide operators with real-time visibility and control across an entire facility or multiple sites. Widely deployed platforms include:
- Ignition by Inductive Automation, popular for its web-based deployment model and open licensing.
- AVEVA System Platform (formerly Wonderware), common in continuous process industries.
- Siemens WinCC, tightly integrated with the S7 PLC range and TIA Portal.
- AVEVA Citect SCADA, used extensively in utilities and infrastructure.
HMI (Human Machine Interface) panels from Siemens, Rockwell, Weintek and Beijer sit at workstations and on the plant floor, giving operators localised control and status information. Manufacturing Execution Systems (MES), defined within the ISA-95 framework, bridge SCADA and ERP layers by tracking production orders, quality data and genealogy.
Industrial Networking Protocols
Communication between field devices, PLCs, SCADA and enterprise systems relies on a stack of industrial protocols, each suited to different layers and use cases.
Fieldbus and Industrial Ethernet
Profibus (Process Field Bus) remains in service at many legacy installations, particularly with Siemens equipment. Its successor, Profinet, runs over standard Ethernet hardware and supports real-time deterministic communication, making it the dominant protocol for new Siemens-based installations. EtherNet/IP performs the same role in Rockwell ecosystems, using the Common Industrial Protocol (CIP) over standard Ethernet.
Modbus RTU and Modbus TCP are the most widely deployed protocols in the world by installed base. Modbus RTU runs over RS-485 serial links; Modbus TCP runs over Ethernet. Both are simple and open, which explains their longevity in instrumentation, drives and energy metering.
OPC-UA: The Modern Integration Standard
OPC Unified Architecture (OPC-UA) has become the preferred standard for secure, platform-agnostic data exchange between automation systems and higher-level applications including SCADA, MES, cloud platforms and analytics tools. Unlike older OPC-DA, which was Windows-dependent and based on DCOM, OPC-UA is cross-platform, supports a rich information model, and includes built-in security through certificate-based authentication and encrypted transport. Most modern PLCs, including the Siemens S7-1500 and Beckhoff TwinCAT systems, expose an OPC-UA server natively.
Key Standards Governing Industrial Automation
Compliance with recognised standards is not optional in most industrial sectors. Understanding which standards apply to a given project defines the engineering approach, documentation requirements and, often, the skills needed on the team.
IEC 61131-3
The foundational programming standard for PLCs and soft controllers. Any competent automation engineer should be able to work in at least two of the five defined languages and understand the execution model.
IEC 61511 and Functional Safety
IEC 61511 governs Safety Instrumented Systems (SIS) in the process industries, covering the full safety lifecycle from hazard and risk assessment through to decommissioning. It is the process-sector application of the broader IEC 61508 functional safety framework. Engineers working on burner management systems, emergency shutdown systems and high-integrity pressure protection systems need to understand Safety Integrity Level (SIL) determination, SIL verification and proof test requirements. For a wider discussion of functional safety hiring in the UK, the article on Functional Safety Recruitment: Finding Engineers with IEC 61508 and ISO 26262 Experience covers the talent landscape in detail.
IEC 62443: Industrial Cybersecurity
IEC 62443 is the international standard series for the security of Industrial Automation and Control Systems (IACS). As OT (Operational Technology) networks become more connected to IT networks and cloud services, the risk of cyber attack on industrial infrastructure has grown considerably. IEC 62443 defines security levels, zones and conduits, and places obligations on both system integrators and asset owners. Engineers with IEC 62443 experience, particularly at the system integrator level (Part 2-4) and asset owner level (Part 2-1), are increasingly sought after.
ISA-88: Batch Control
ISA-88 (also known as S88) defines a physical and procedural model for batch processes, widely used in pharmaceuticals, specialty chemicals and food manufacturing. Its concepts of recipes, equipment phases and procedural elements underpin how batch control software is structured on systems from Siemens, Rockwell and DeltaV.
Industrial Automation and the Move Towards IIoT and Edge Computing
The boundary between traditional industrial automation and embedded or IoT engineering is narrowing. Edge computing devices, running Linux-based stacks built with Yocto or Buildroot on processors such as the NXP i.MX series or TI AM series SoCs, are now deployed at the plant floor to preprocess data before sending it to cloud analytics platforms. This convergence requires engineers who understand both the OT world (determinism, reliability, safety) and the IT world (containerisation, MQTT, REST APIs, cloud connectivity).
Protocols such as MQTT (often paired with the Sparkplug B specification for industrial semantics) and OPC-UA over MQTT are becoming the standard way to move data from edge nodes to cloud or on-premises data historians. Platforms such as Ignition Edge and Siemens Industrial Edge are designed explicitly to sit at this OT/IT boundary.
For engineering leaders building teams that span automation and embedded development, the articles on IoT Hiring Trends: What UK Companies Are Looking for in Embedded IoT Engineers and Embedded Linux Engineering: Why the Talent Gap Is Widening provide useful context on where the market is moving.
Building and Hiring Automation Teams in the UK
Finding experienced automation engineers in the UK is genuinely competitive. Demand is being driven by capital investment programmes in pharmaceutical manufacturing (including OSD and biotech facilities), water infrastructure upgrades, energy transition projects and reshoring of advanced manufacturing. At the same time, many experienced controls engineers are approaching retirement age, creating a structural gap that is not easily filled by graduates alone.
Key skills to assess when hiring:
- PLC programming experience (specify platforms relevant to your installed base)
- SCADA configuration and historian integration
- Industrial networking and protocol knowledge (Profinet, EtherNet/IP, OPC-UA)
- Functional safety experience where SIS applications are involved
- IEC 62443 awareness for connected or networked installations
- FAT/SAT experience and documentation standards (GAMP 5 in regulated industries)
- Understanding of P&IDs and instrument loop diagrams
Specialist recruitment for these roles requires a recruiter who understands the difference between a Siemens DCS engineer and a Rockwell PLC programmer, and who can assess a CV for genuine project depth rather than surface-level platform familiarity. Generic recruitment processes tend to produce poor results for niche technical roles, a point explored in How Long Does It Take to Hire a Specialist Engineer? UK Benchmarks 2026.
Vertech Group operates specialist recruitment practices in both Industrial Automation and Controls and Embedded and Product Engineering, placing engineers across sectors including energy, defence, pharmaceuticals, food and beverage, advanced manufacturing and infrastructure. If you are building an automation team or looking for your next controls engineering role, the team works across permanent, contract and interim positions across the UK.
Frequently Asked Questions
What is industrial automation and why does it matter for UK manufacturers?
Industrial automation is the use of control systems, software and machinery to perform manufacturing processes with minimal human intervention. It encompasses technologies such as PLCs, SCADA systems, robotics and industrial networking protocols working together to improve efficiency, consistency and safety. For UK manufacturers, automation is increasingly critical for remaining competitive against lower-cost international production. It also addresses persistent skilled labour shortages by enabling higher output with leaner teams. The UK government's Made Smarter initiative has further accelerated adoption across sectors including automotive, food and beverage, and pharmaceuticals.
What is the difference between a PLC and a SCADA system?
A PLC, or Programmable Logic Controller, is a ruggedised industrial computer that directly controls machinery and processes by reading inputs from sensors and executing programmed logic to drive outputs such as motors and valves. SCADA, which stands for Supervisory Control and Data Acquisition, operates at a higher level, collecting data from multiple PLCs and other field devices to provide operators with a centralised monitoring and control interface. In practical terms, the PLC is the workhorse executing real-time control loops, while SCADA provides visibility, data logging and alarm management across an entire facility or network of sites. The two technologies are complementary and are commonly deployed together. Understanding the boundary between them is essential for automation engineers designing or maintaining integrated systems.
Which industrial networking protocols should automation engineers know?
The most widely used industrial networking protocols include Ethernet/IP, PROFINET, Modbus TCP and EtherCAT, each with different strengths depending on the application. PROFINET is dominant in European manufacturing environments and integrates tightly with Siemens and other European PLC platforms. Ethernet/IP is prevalent in North American-influenced plants and is supported by Rockwell Automation systems. Modbus TCP remains common in legacy installations and simpler field device communications due to its simplicity and openness. EtherCAT is favoured in high-speed motion control applications where deterministic timing is critical. Engineers working across multiple sites or sectors will frequently encounter several of these protocols and should be comfortable with their configuration and troubleshooting.
What standards govern industrial automation deployments in the UK?
Several key standards underpin safe and interoperable automation deployments in the UK. IEC 61508 defines the functional safety requirements for electrical, electronic and programmable electronic safety-related systems, and it forms the basis for sector-specific standards such as IEC 61511 for the process industries and IEC 62061 for machinery. The IEC 61131-3 standard specifies the programming languages used for PLCs, including Ladder Diagram, Structured Text and Function Block Diagram, helping to ensure portability of control logic across different hardware platforms. For industrial communications, the IEC 61784 series covers fieldbus and industrial Ethernet protocol profiles. Compliance with these standards is typically required on larger projects and is increasingly expected by clients in regulated sectors such as pharmaceuticals and energy.
What engineering roles are most in demand within industrial automation?
The most sought-after roles in UK industrial automation currently include PLC and SCADA engineers, control systems engineers, robotics integration engineers and functional safety engineers holding TÜV certification. There is also strong demand for engineers with expertise in industrial cybersecurity as OT network security becomes a board-level concern. Commissioning engineers with hands-on site experience are consistently difficult to recruit, particularly those comfortable working across multiple automation platforms such as Siemens, Rockwell and Schneider Electric. As digital transformation programmes accelerate, roles bridging OT and IT such as MES engineers and digital twin specialists are growing rapidly. Candidates with both electrical engineering foundations and software skills are particularly valued across the sector.
How is Industry 4.0 changing the skills required for automation engineers?
Industry 4.0 is driving a significant shift in the skills profile expected of automation engineers, moving beyond traditional PLC programming and panel building towards a broader technology stack. Engineers are now expected to understand industrial IoT connectivity, edge computing and cloud data platforms alongside their core control systems knowledge. Data analytics and the ability to work with historians and manufacturing execution systems are becoming standard requirements rather than differentiators. Cybersecurity awareness is essential as OT and IT networks converge, and engineers who can assess and mitigate vulnerabilities in industrial control systems are in high demand. Communication and project management skills are also increasingly valued as automation engineers are expected to engage with business stakeholders and lead cross-functional implementation projects.
How should manufacturing leaders approach building an automation engineering team?
Building an effective automation engineering team requires a clear skills audit aligned to the specific technologies and platforms deployed or planned within your facility. Leaders should distinguish between the need for deep specialists, such as functional safety engineers or robotics programmers, and generalist control systems engineers who can work flexibly across multiple disciplines. Partnering with a specialist engineering recruitment consultancy with sector-specific knowledge significantly reduces time-to-hire and improves candidate quality, particularly for niche or senior roles. Structured onboarding and clear career development pathways are critical for retention, as experienced automation engineers are in short supply and frequently targeted by competitors. A blended workforce model using permanent hires for core roles and contract engineers for project peaks is a common and effective approach across UK manufacturing.