During implementation of an architecture, as more facts become known, it is possible that the original Architecture Definition and requirements are not suitable or are not sufficient to complete the implementation of a solution. In these circumstances, it is necessary for implementation projects to either deviate from the suggested architectural approach or to request scope extensions. Additionally, external factors - such as market factors, changes in business strategy, and new technology opportunities - may open up opportunities to extend and refine the architecture.

In these circumstances, a Change Request may be submitted in order to kick-start a further cycle of architecture work.

Typical contents of a Change Request are:

• Description of the proposed change
• Rationale for the proposed change
• Impact assessment of the proposed change, including:
  • Reference to specific requirements
  • Stakeholder priority of the requirements to date
  • Phases to be revisited
  • Phase to lead on requirements prioritization
  • Results of phase investigations and revised priorities
  • Recommendations on management of requirements
• Repository reference number