The European Union’s NIS2 Directive aims to raise the baseline of cybersecurity across Europe’s essential sectors. Understanding its implications is key for any organisation seeking to protect operations, maintain continuity, and demonstrate accountability in an increasingly interconnected landscape.
This article explores what the NIS2 Directive means for organisations operating industrial and OT environments. It addresses common questions and challenges around compliance, clarifies how NIS2 applies to connected operational systems, and offers practical guidance on strengthening resilience, governance, and supply chain assurance in line with its requirements.
- What is the NIS2 directive?
- Who does NIS2 apply to?
- Why NIS2 matters for OT security
- Key NIS2 Directive requirements explained
- Aligning NIS2 with established OT security frameworks
- Steps to prepare for NIS2 compliance
- Common challenges in achieving NIS2 compliance
- Benefits beyond compliance
- How ready are you?
What is the NIS2 directive?
The Network and Information Systems Directive (NIS2) is the European Union’s updated cybersecurity legislation, replacing the original 2016 NIS Directive. It came into force in 2023, with EU member states required to transpose it into national law by October 2024.
The goal of NIS2 is simple: to strengthen cybersecurity resilience and incident response across essential and important sectors that underpin European society and the economy.
Where the original NIS directive focused on a limited set of critical services, NIS2 broadens that scope to include far more industries — from manufacturing and energy to healthcare, transport, and digital infrastructure.
Who does NIS2 apply to?
NIS2 applies to two main categories of entities:
- Essential entities, such as energy providers, manufacturers of critical goods, water utilities, healthcare providers, and transport operators.
- Important entities, including food production, waste management, chemicals, digital services, and suppliers in key industrial supply chains.
Even mid-sized manufacturers and service providers now fall within the scope of the directive – meaning thousands of organisations that previously sat outside cybersecurity regulations will soon face mandatory obligations under NIS2.
For industrial businesses, this represents a new level of visibility and accountability around OT security and resilience.
Why NIS2 matters for OT security
In many organisations, OT systems — from PLCs and HMIs to SCADA networks — were historically isolated from IT environments.
But as connectivity, analytics, and cloud integrations have increased, those once-closed systems are now exposed to cyber risks and supply chain dependencies.
NIS2 brings OT into direct regulatory focus.
It requires organisations to treat cybersecurity not as an IT issue, but as a core operational and governance responsibility. That means ensuring visibility of industrial assets, securing control networks, and embedding incident response processes that account for the unique realities of OT environments.
Key implications for OT teams include:
- Stronger network segmentation between IT and OT
- Comprehensive asset discovery and risk mapping
- Documented incident reporting workflows
- Supply chain assurance across integrators, OEMs, and service partners
- Clear board-level accountability for cyber resilience
For many industrial businesses, these requirements highlight the need to unify IT and OT governance — a shift already encouraged by frameworks like IEC 62443 and NIST CSF.
Key NIS2 Directive requirements explained
The Directive outlines several major obligations. Below is a simplified summary of how they relate to OT environments.
| Requirement | Description | What It Means for OT Security |
| Risk Management & Security Measures | Organisations must implement policies for risk analysis, incident handling, business continuity, and supply chain security. | Establish structured OT risk assessments, asset inventories, and network segmentation aligned with frameworks like IEC 62443. |
| Incident Reporting | Incidents must be reported within 24 hours (early warning) and detailed follow-up within 72 hours. | OT teams need clear escalation paths, visibility tools, and defined reporting procedures that don’t disrupt operations. |
| Governance & Accountability | Senior leadership bears personal responsibility for compliance. | The board must ensure OT cyber risks are discussed at governance level, not left to engineering teams alone. |
| Supply Chain Security | Entities must manage third-party and supplier cybersecurity risks. | Evaluate and monitor suppliers, system integrators, and contractors for NIS2-aligned controls. |
| Supervision & Enforcement | National authorities have powers to audit, investigate, and issue fines. | Compliance documentation and evidence of risk management will be required on request. |
In short, NIS2 makes OT security measurable, auditable, and enforceable.
Aligning NIS2 with established OT security frameworks
While the NIS2 Directive defines what must be achieved, it does not specify how. That’s where established frameworks come in.
Frameworks such as IEC 62443, NIST Cybersecurity Framework (CSF), and ISO/IEC 27001 provide the structured methods and controls to demonstrate compliance.
- IEC 62443 – Offers detailed technical guidance for securing industrial automation and control systems.
- NIST CSF – Provides a flexible, risk-based management framework built around Identify, Protect, Detect, Respond, and Recover.
- ISO/IEC 27001 – Delivers enterprise-wide governance and certification capabilities for cybersecurity maturity.
By aligning NIS2 obligations with these frameworks, organisations can translate regulatory expectations into operational controls and measurable outcomes.
Steps to prepare for NIS2 compliance
Becoming NIS2-ready doesn’t happen overnight. But by taking a structured approach, organisations can build compliance capability while improving overall OT security resilience.
1. Conduct a NIS2 readiness or gap assessment
Map your current controls, policies, and incident response processes against NIS2 requirements. Identify where shortfalls exist — particularly around asset visibility, governance, and supply chain oversight.
2. Build an OT asset inventory
You can’t protect what you don’t know. Use passive discovery tools to identify connected devices, legacy systems, and communication pathways without disrupting production.
3. Strengthen governance and accountability
Define roles and responsibilities at board and operational levels. NIS2 makes leadership accountable, so ensure executive teams understand their obligations and reporting lines.
4. Align IT and OT security processes
Unify risk management, access control, and incident response across IT and OT environments. Avoid siloed approaches that leave gaps in detection and communication.
5. Develop incident reporting procedures
Create clear processes for early warning and follow-up reporting within 24 and 72 hours, as required by NIS2.
Regular drills and tabletop exercises can help ensure readiness.
6. Engage your supply chain
Conduct due diligence on vendors, system integrators, and maintenance partners. Ensure third-party contracts include explicit cybersecurity and reporting requirements.
7. Monitor and continuously improve
Implement ongoing monitoring, audits, and review cycles. Use metrics and maturity models to track progress over time and adjust controls as your risk landscape evolves.
Common challenges in achieving NIS2 compliance
Legacy systems
Older industrial systems often can’t be patched or updated. Use compensating controls like network segmentation, strict access control, and real-time monitoring.
Lack of visibility
Many OT environments lack full network visibility. Deploy passive asset discovery and intrusion detection to identify blind spots safely.
Resource constraints
Smaller organisations may struggle with staffing or budget limitations. Prioritise high-impact areas first — asset visibility, governance, and response capability — before scaling up.
Fragmented IT/OT ownership
Bridging cultural and technical gaps between IT and OT teams is essential. Cross-functional governance and shared KPIs can help align objectives.
Benefits beyond compliance
While the NIS2 Directive introduces legal accountability, the benefits of compliance extend far beyond avoiding fines. Organisations that take a proactive approach to OT cybersecurity gain:
- Greater operational resilience and reduced downtime
- Improved insurance eligibility through demonstrable control maturity
- Enhanced supply chain trust — increasingly a differentiator in vendor selection
- Better cross-team collaboration between IT, OT, and compliance functions
Ultimately, NIS2 compliance is a competitive advantage — positioning your organisation as a trustworthy and resilient partner in the industrial ecosystem.
How ready are you?
The NIS2 Directive marks a major turning point in how Europe protects its critical and industrial systems.
For operators of OT environments, it brings both challenge and opportunity — elevating cybersecurity from a technical concern to a strategic business priority.
By aligning with frameworks like IEC 62443, NIST CSF, and ISO 27001, and by taking early action to assess readiness, organisations can move beyond box-ticking to achieve genuine, sustainable cyber resilience.
If you’re interested in exploring how NIS2-ready your organisation is, why not start by taking our free maturity assessment to get a detailed understanding of where your organisation currently stands? And once you’ve done that, you might want to book a free consultation with one of the Harpoon team to discuss your results and look at how to start getting NIS2 compliant.
