Phase H (Architecture Change Management) monitors the implemented architecture for change drivers and classifies incoming change requests. It is NOT about implementing changes — it is about maintaining architectural control by deciding how to respond to change.
Phase H operates after implementation is complete. The architecture is now the "current" architecture, and Phase H monitors for factors that might require it to evolve.
- ▸📡 Monitors technology changes, business drivers, and governance outputs
- ▸📥 Receives Architecture Change Requests from stakeholders and operations
- ▸🔍 Classifies each change: Simplification, Incremental, or Re-architecting
- ▸🔄 Minor changes handled via Architecture Change Request (no new ADM cycle)
- ▸🔁 Major changes trigger a NEW ADM cycle (back to Phase A or Preliminary)
- ▸📋 Updates Architecture Repository with change decisions
- ▸🔗 Prevents uncontrolled architecture drift over time
See how CDIPD classifies real-world change requests received after DWMS, PayFlask, and VSSC were implemented. Click each scenario to reveal the classification and rationale:
Phase H monitors and classifies architecture changes — it does NOT implement them. Only Re-architecting triggers a full new ADM cycle. Incremental changes are handled via Architecture Change Requests without a new cycle. Phase H exists to prevent uncontrolled architecture drift. The Architecture Board approves or rejects change requests in Phase H.
TOGAF defines three types of architecture change, and knowing when each applies is critical for exam scenarios.
- ▸✂️ Simplification: Removes complexity or obsolete items. May not require a new ADM cycle.
- ▸🔄 Incremental: Small, bounded changes to the existing architecture. Handled via Architecture Change Request. No new ADM cycle needed.
- ▸🔁 Re-architecting: Fundamental change to the architecture. ALWAYS triggers a new full ADM cycle.
- ▸⚠️ Key exam question: "Which change type triggers a new ADM cycle?" = Re-architecting (ONLY)
- ▸📌 Simplification and Incremental can be handled within the current architecture governance
Architecture Change Requests in Phase H can be triggered by many different sources — these trigger sources are tested in scenario questions.
- ▸💼 Business change: new products, services, mergers, regulatory changes
- ▸🖥️ Technology change: new platform versions, vendor end-of-life, emerging technology
- ▸⚙️ Implementation issues: problems discovered in Phase G that require architecture change
- ▸📊 Performance: implemented system not meeting architecture-specified performance targets
- ▸🔒 Security: new vulnerabilities identified requiring architecture response
- ▸📋 Governance: Architecture Board identifies drift or non-conformance in operating system