A practical template for replacing legacy systems without blindly rebuilding them.
Especially useful for large, poorly documented legacy systems.
Best suited for:
Business Analysts, System Analysts, Architects, Product Managers, Technical Leads and modernization / migration teams.
Start with the Master Map to define domains, actors, major use cases and dependencies.
Then duplicate a Domain Deep Dive for each domain and work through:
Actors → Use Cases → Journey → AS-IS → TO-BE → Integrations / APIs → Evidence / Gaps → Roadmap
Do not document the whole legacy system.
Focus on one question:
What do we actually need in the new solution — and why?
