As cyber threats continue to intensify and information systems grow more complex, interconnected and constantly evolving, having a clear and structured view of your IT landscape is no longer optional. Information system mapping has become a cornerstone of any robust cybersecurity framework.
In France, the ANSSI (National Cybersecurity Agency of France) emphasizes the importance of maintaining an accurate, structured and continuously updated IT system map. A reliable mapping repository enables organizations to identify vulnerabilities, secure data flows, prioritize protection measures and reinforce long-term resilience, whether in the public or private sector.
This article explains ANSSI’s recommendations for IT system mapping and shows how myCarto provides a practical, operational response fully aligned with these cybersecurity requirements.
Why IT system mapping is a cybersecurity prerequisite according to ANSSI
Mapping your information system is not about drawing a static diagram or producing a one-off overview document. It involves building a living, shared and comprehensive representation of:
- Business processes
- Applications and software components
- Databases and data flows
- Infrastructure, servers and network zones
- Internal and external interconnections
This holistic visibility is essential to:
- Detect technical and organizational vulnerabilities
- Anticipate cyber threats and attack scenarios
- Implement segmentation and access control measures
- Respond effectively to incidents, crises or compliance audits
As highlighted in ANSSI’s cybersecurity guidance, a relevant and up-to-date IT mapping framework is a necessary foundation for any security initiative.
A relevant information system mapping is a necessary prerequisite for any security initiative.”
ANSSI – National Cybersecurity Agency of France (French cybersecurity authority)
Without a reliable IT system mapping, any security initiative relies on incomplete, or even incorrect, assumptions.
ANSSI recommendations for structured IT system mapping
Start with a defined and controlled scope
According to guidance from the ANSSI, building a reliable IT system mapping framework should follow a structured and progressive four-step methodology.
- Define a clear and controlled mapping scope:
ANSSI recommends starting with a limited perimeter focused on a critical domain (for example, a strategic service, a trusted network zone, or a sensitive business process) to avoid dispersion and ensure clear governance from the very beginning.
- Model data using a multi-view approach:
It is essential to structure the mapping into distinct layers, each serving its own purpose. The business view represents processes and their owners; the application view details software, databases, and data flows; the technical view covers infrastructure, network zones, and equipment; and the flow view makes communications and external accesses visible. Together, these views create a coherent and comprehensive picture of the information system.
- Consolidate data with transparency and collaboration:
Any viable mapping requires active consolidation of information across different teams (IT, business, security) to validate the representations, correct errors, and obtain a reliable, shared view.
- Keep the mapping alive over time:
ANSSI emphasizes that a mapping quickly becomes obsolete if it is locked in a PowerPoint or Excel file. Therefore, effort must be focused on implementing a formal update process whenever significant changes occur in the information system, ensuring that it remains truly operational.
A common language for a shared repository
One of the key points emphasized by ANSSI is that mapping should not be reserved for a small, isolated group: it must be understood by everyone, from the IT department to the CISO, and be interfaced with business stakeholders and operators. Defining a repository of terms, definitions, and levels of granularity promotes collective understanding and serves as a foundation for governance, documentation, and standardization.
Sustainable and interoperable tools, beyond obsolete office software
Manual methods, such as mapping in Excel, PowerPoint, or Visio, do not ensure reliability, timely updates, or the collaboration necessary to manage the information system effectively. Furthermore, ANSSI recommends the use of specialized software solutions that provide modeling, interconnection with other tools (CMDB, GRC, SIEM), dynamic filters, change history tracking, and automated exports to guarantee the long-term usability and operational value of the mapping.
How myCarto Meets ANSSI IT System Mapping Guidelines
myCarto has been designed to perfectly align IT system mapping practices with ANSSI requirements, across four key areas:
Multi-view modeling, compliant with the ANSSI methodology
myCarto enables the representation of:
- Business views (processes, functional entities)
- Application views (software, interconnections)
- Technical views (infrastructure, servers, zones)
- Flow views (data, communications)
Each object is structured and typed according to a configurable metamodel, allowing adaptation to your organization and internal standards.
Collaboration, traceability, and governance
- Multi-user work on the same repository
- Modification history tracking
- User rights management
- Compliance report exports
A secure and sovereign solution
- Hosting in France
- SSO connection, data encryption
- GDPR-compliant and meeting CNIL requirements
- Ready to integrate with a SIEM, GRC tool, or CMDB
Best Practices for ANSSI-Compliant IT System Mapping
- Best Practices for ANSSI-Compliant IT System Mapping
- Start with a critical perimeter validated with the IT security management (e.g., a sensitive business process or a network zone to secure).
- Involve the right stakeholders from the beginning (CISO, IT architects, business units, infrastructure teams) to ensure coherence.
- Leverage existing resources (CMDB, previous projects, existing documentation) to accelerate initial deployment.
- Plan regular updates following IT system evolutions or as part of an annual review.
- Integrate mapping into a governance cycle, linked with risk management and compliance initiatives (ISO 27001, NIS2…).
Implement an ANSSI-Compliant IT System Mapping
FAQ : IT mapping and cybersecurity
Can IT mapping prevent a cyberattack?
IT system mapping cannot prevent a cyberattack on its own, but it plays a key role in reducing vulnerabilities and limiting impact. By providing a clear view of assets, data flows, and dependencies, it helps identify sensitive areas, prioritize security actions, and respond quickly in the event of an incident.
How often should an IT system map be updated?
According to cybersecurity best practices and the recommendations of the ANSSI, IT system mapping should be updated whenever significant changes occur within the information system. Ideally, it should be part of a continuous improvement approach, supported by tools that enable automation and collaborative updates.
Is it necessary to map the entire information system?
Ultimately, the goal is to obtain a comprehensive mapping of the entire information system. However, it is recommended to begin with business-critical perimeters and progressively extend the coverage. The level of detail should be aligned with the criticality of the mapped domains.
Does IT mapping replace a CMDB?
No, IT system mapping does not replace a CMDB, it complements it. A CMDB provides a structured database of assets, while mapping delivers a visual, cross-functional, and operational view that supports the analysis of interactions, data flows, and dependencies. It is recommended to interface mapping tools with other systems that describe and manage the IT landscape.
What ROI can be expected from IT mapping in cybersecurity?
A structured IT system mapping enables faster incident response, reduced downtime, more effective prioritization of security actions, and informed decision-making in critical or regulatory situations.
Conclusion
IT system mapping is a fundamental building block of any cybersecurity strategy.
ANSSI provides a solid reference framework for structuring IT system mapping, but its operational implementation requires a dedicated tool capable of turning these principles into concrete actions.
myCarto fully embraces this approach by delivering an IT system mapping solution aligned with ANSSI guidelines, collaborative, sustainable, and secure.
