System Landscape Diagram
A diagram showing all the systems within an enterprise or domain and how they relate to each other, providing a bird's-eye view of the IT estate and its interconnections.
Purpose
The system landscape provides visibility of the entire IT estate, helping identify dependencies, redundancies, and integration complexity. It supports strategic planning by showing where systems overlap or where gaps exist.
When to Use
Create during pre-discovery or discovery when understanding the existing landscape. Update it as new systems are introduced or retired. Essential for enterprise architecture planning and rationalisation exercises.
How to Build
Start by cataloguing all systems in the domain or enterprise. Group them by business capability or domain area. For each system, note its name, primary purpose, technology platform, and owner.
Arrange systems on the diagram grouped by domain or capability area. Use consistent shapes and colours to distinguish system types (e.g., custom-built vs COTS vs SaaS).
Draw integration lines between systems that exchange data or depend on each other. Label with the integration mechanism (API, file transfer, database link, manual).
Highlight the system under consideration (if this supports a specific project) and show how it fits into the broader landscape.
Include a legend explaining your notation and colour coding.
Tips
- Use ArchiMate notation for enterprise-level landscapes for consistency with TOGAF.
- Colour-code by lifecycle status: green for strategic, amber for tactical, red for retirement.
- Include data classification labels where relevant for security planning.
- Keep it at one level of abstraction — don't mix enterprise and component views.
- Update quarterly as the landscape evolves.
Common Mistakes
- Trying to show every system in the entire organisation on one diagram.
- Not keeping it updated as systems are added or retired.
- Omitting shadow IT or departmental systems that create hidden dependencies.
- Not showing the direction and nature of data flows between systems.
- Making it too detailed — this should be a strategic view, not a technical one.
Government Context
In UK government, system landscape diagrams support the Technology Code of Practice principle of sharing and reusing. They help identify where cross-government platforms could replace departmental solutions. CDDO uses landscape views for digital spend oversight. They are essential for Legacy IT risk assessments and the government's commitment to reducing technical debt across departments.