Think, Document, Reuse: these are the purposes of doing Enterprise Architecture, and also the steps.
Creating architectural documents and diagrams forces people to think about their business activities and IT requirements. A rigorous modeling language will prompt consideration of new ideas and things you were trying to avoid thinking about.
Architecture needs to be written down. A document or diagram may specify:
- Exactly what to implement;
- Exactly what was implemented, so it is easier to maintain;
- Rationale for choices made, to avoid going through the decision process again.
Architecture building blocks can be reused, if they are documented and stored in a permanent, easy-to access location. An architect should consider what can be reused before creating new architecture.