What is an ISMS?
An ISMS (Information Security Management System) is a management system for information security, comprising policies, processes, procedures, roles and controls that systematically protect business information from threats such as unauthorised access, loss or sabotage.
The ISMS helps organisations to structurally organise, manage and improve information security, in line with standards such as ISO 27001 and IEC 62443.
🎯 Purpose of an ISMS
- Identifying and managing information security risks
- Safeguarding availability, integrity and confidentiality of data (the CIA triad)
- Compliance with laws and regulations (e.g. NIS2, AVG, BIO)
- Building awareness and accountability within the organisation
🧱 Key components of an ISMS
| Component | Description |
|---|---|
| Risk assessment | Systematically analysing threats and vulnerabilities |
| Policy & Governance | Guidelines, responsibilities and mandates |
| Controls | Technical and organisational measures (e.g. Firewall, VPN, SIEM) |
| Awareness & training | Making employees aware of risks and behaviour |
| Audits & Monitoring | Regular evaluation of effectiveness and Compliance |
| Continuous improvement | In line with the PDCA cycle (Plan-Do-Check-Act) |
🏭 ISMS in an OT context
In an industrial environment, an ISMS is applied to systems such as:
- SCADA, PLCs, Historian, MES and sensor networks
- The Zone and Conduits model as an architectural foundation
- Specific standards such as IEC 62443 for OT security
- Agreements on access, patch management, Logging and Remote Access
An ISMS connects technical IT/OT security with organisation-wide policy management.
📌 In summary
An ISMS is the framework with which organisations organise, monitor and improve information security. It combines policy, risk analysis and technical measures, and forms the basis for compliance with standards such as ISO 27001, BIO or IEC 62443.