Stage 4 of 8
Information Systems Architecture
This stage treats data and applications as a joined architectural problem. It uses TOGAF Phase C and several Series Guides to make information authority, metadata, integration, and application boundaries explicit.
Read this stage in sequence on the first pass. The point is to sharpen judgement through one concrete artefact and one practical decision, not to accumulate isolated notes.
What this stage covers
Use the modules in order. The groupings below organise the sequence without changing it.
Set the Phase C frame
Start with the role of data and application architecture, then make information mapping and authority boundaries explicit.
- 30 min. Explain how TOGAF treats Phase C
- 25 min. Use information mapping to reason about enterprise data
- 25 min. Define authority, stewardship, and source of truth correctly
Build depth in information architecture
Move from master data and metadata into analytics and application boundaries so the architecture becomes operationally useful.
- Module 4Customer master data management25 min. Explain MDM through a TOGAF lens
- 25 min. Explain utility asset and network data concerns
- 20 min. Explain metadata management in practical terms
- 20 min. Connect analytics architecture to decision quality
- 25 min. Use application architecture to reason about boundaries and responsibilities
Select, integrate, and apply
Finish with integration, ABB versus SBB, and the London LTDS and CIM application.
- 20 min. Explain integration choices and their architectural consequences
- 25 min. Apply Phase C to the London LTDS and CIM case
Why this stage matters
Phase C is where enterprise architecture begins to influence delivery in a visible way. Weak work here produces duplicated authority, brittle integrations, and dashboards built on confused data.
London threads in this stage
- LTDS publication and CIM alignment
- Customer and asset authority boundaries across multiple systems
- How information architecture supports planning, visibility, and regulatory evidence
Artefacts you should be able to defend
- Information-authority map
- Application landscape and integration map
- Building-block selection notes
Primary stage artefact
Information-authority map
Treat this as the main artefact the stage should sharpen. If you can explain who it is for, what decision it affects, and what evidence it depends on, the stage is doing real work.
My view
The phrase source of truth is overused. Most enterprises have authority boundaries, publication rules, and synchronisation patterns, not one magical master system.
Stage workspace
The workspace contains eleven practice tools that reinforce the skills covered in each stage. Use them alongside the reading flow or revisit them during revision.