Virtualisation

Virtualisation is a technology in which physical hardware resources are abstracted so that multiple virtual systems can run simultaneously on the same physical infrastructure. Within OT and Industrial Automation, virtualisation is increasingly applied to SCADA, Historian systems, MES, HMI, Soft PLC platforms, engineering stations and industrial edge environments.

Where Industrial Automation was traditionally based on dedicated hardware, modern OT architectures are shifting more and more towards software-defined infrastructures. This produces closer integration between IT and OT platforms within IT OT Convergence.

Virtualisation delivers benefits such as:

• hardware consolidation
• Scalability
• Redundancy
• faster provisioning
• Snapshot Recovery
• Lifecycle Management
• Disaster Recovery
• test and simulation environments

At the same time, virtualisation introduces new challenges around real-time behaviour, availability, Cybersecurity and operational complexity.

⚙️ Basic principles of virtualisation

In virtualisation, physical hardware is logically divided into multiple virtual environments.

Key components:

A Hypervisor manages:

• CPU scheduling
• memory allocation
• storage access
• network virtualisation
• hardware abstraction

This allows multiple systems to run independently on the same hardware.

🏗️ Types of virtualisation

Type 1 hypervisor

Bare-metal hypervisors run directly on hardware.

Examples:

• VMware ESXi
• Microsoft Hyper-V
• KVM
• Xen

Advantages:

• high performance
• better isolation
• lower overhead
• suitable for production environments

Within OT, Type 1 hypervisors are dominant.

Type 2 hypervisor

Runs on top of a standard operating system.

Examples:

• VMware Workstation
• VirtualBox

Used for:

• test environments
• OT labs
• engineering
• simulation

Not ideal for production processes due to additional Latency and dependency on the host OS.

Containerisation

Containers virtualise applications rather than entire operating systems.

Examples:

• Docker
• Podman
• Kubernetes

Advantages:

• low overhead
• fast deployment
• scalability
• cloud-native architectures

Applications within OT:

• edge analytics
• MQTT brokers
• protocol gateways
• OT monitoring
• microservices

Containers are becoming increasingly important within Edge Computing.

🧠 Virtualisation within OT

Within industrial automation, various OT workloads are virtualised.

Frequently virtualised systems

⚡ Real-time challenges

OT systems often require Deterministic Behaviour.

Virtualisation, however, introduces additional layers:

Application    │Guest OS    │Hypervisor    │Physical Hardware

Each extra layer can influence:

• Latency
• Jitter
• interrupt handling
• scheduling
• real-time synchronisation

Problems arise particularly with:

• Motion Control
• Safety systems
• turbine control
• high-speed IO
• real-time Fieldbuses

For this reason, some systems remain dependent on dedicated hardware.

🔌 Industrial communication and virtualisation

Virtualised OT systems often use:

• OPC UA
• MQTT
• Modbus TCP
• ProfiNET
• Ethernet IP

Virtualisation affects network behaviour:

Real-time protocols such as EtherCAT are often difficult to virtualise fully due to strict timing requirements.

🖥️ Virtual SCADA environments

Virtualisation is widely applied to SCADA systems.

Advantages:

• central hosting
• easier management
• snapshots
• fast recovery
• redundancy
• hardware independence

Typical Architecture:

Virtual SCADA Servers        │Virtual Historian        │Virtual OPC Servers        │Industrial Network

Many SCADA platforms now officially support:

• VMware
• Hyper-V
• KVM

☁️ Hyperconverged OT infrastructure

More and more OT environments use hyperconverged infrastructure.

This combines:

• compute
• storage
• networking
• virtualisation

Advantages:

• scalability
• redundancy
• centralised orchestration
• simpler management

Typical technologies:

• VMware vSAN
• Nutanix
• Azure Stack HCI

Applied in:

• power plants
• water treatment
• production environments
• data centres

🔒 Cybersecurity implications

Virtualisation significantly changes the OT attack surface.

New risks

Virtualisation creates additional attack surfaces:

• management interfaces
• orchestration layers
• APIs
• storage fabrics
• virtual switches

🛡️ Hardening of virtualised OT

Key controls:

• Network Segmentation
• Industrial Firewall
• dedicated management VLANs
• MFA
• RBAC
• hypervisor hardening
• encrypted storage
• secure snapshots
• Logging
• Security Monitoring

In addition, strict separation is important between:

• production OT
• management environments
• engineering
• Backup infrastructure

🔄 High Availability and redundancy

Virtualisation enables advanced redundancy.

Frequently used techniques

Within critical infrastructures, HA solutions are essential.

🧪 Test, OTAP and simulation environments

Virtualisation is ideal for:

• OTAP
• FAT tests
• SAT tests
• simulation
• cyber ranges
• training
• Digital Twin environments

Advantages:

• fast provisioning
• reproducible configurations
• rollback capability
• safe test isolation

OT engineers can simulate complete process environments without physical hardware.

📦 Storage virtualisation

OT systems generate large amounts of data.

Examples:

• historians
• trends
• alarms
• audit logs
• video
• process data

Virtualisation often uses:

• SAN
• NAS
• vSAN
• software-defined storage

Key considerations:

⚠️ Operational risks

Single point of failure

Consolidation increases risks.

Failure of a single host can impact:

• multiple SCADA systems
• historians
• OPC servers
• engineering stations

The following are therefore needed:

• redundant hosts
• cluster architectures
• failover mechanisms
• backup strategies

Resource contention

Virtual systems share hardware.

Issues:

• CPU starvation
• memory pressure
• storage congestion
• network saturation

Consequences:

• increased Latency
• higher Jitter
• process delay
• HMI freezes
• SCADA timeouts

🏭 Practical applications

Manufacturing industry

Virtualisation for:

• SCADA clusters
• MES platforms
• quality systems
• Historian servers

Energy supply

Applications:

• substation servers
• EMS systems
• central monitoring
• analytics

Water sector

Use cases:

• remote telemetry
• pumping station monitoring
• redundant SCADA

Building Automation

Virtual:

• BMS
• HVAC servers
• energy management
• alarm servers

📡 Edge virtualisation

Within Edge Computing, micro-virtualisation is growing strongly.

Edge nodes combine:

• Soft PLCs
• MQTT brokers
• AI inferencing
• OPC UA
• protocol gateways

Technologies:

• lightweight hypervisors
• containers
• Kubernetes edge
• K3s

This produces flexible OT edge platforms.

🛠️ Lifecycle management

Virtualisation simplifies management processes.

Key advantages:

• template deployment
• central patching
• Version Control
• automated backups
• provisioning automation

Integration with:

• Configuration Management
• Patch Management
• Disaster Recovery
• Business Continuity

🛡️ Relevant standards and guidelines

Key standards:

For safety-critical workloads, additional restrictions often apply.

📈 Trends and developments

Key developments:

• software-defined OT
• containerised SCADA
• virtual PLCs
• cloud-native OT
• edge orchestration
• Kubernetes in OT
• hyperconverged infrastructure
• AI-enabled infrastructure

Virtualisation forms a fundamental building block for modern digital industrial architectures.

🎯 Conclusion

Virtualisation has fundamentally changed Industrial Automation by decoupling OT systems from dedicated hardware. This produces more flexible, scalable and efficiently managed OT infrastructures.

Within modern IT OT Convergence environments, virtualisation forms the basis for Edge Computing, software-defined automation, High Availability and modern data integration.

At the same time, virtualisation introduces new challenges around real-time behaviour, Cybersecurity, availability and operational complexity. Successful implementation therefore requires a careful balance between IT flexibility and OT reliability.