Nothing ever goes exactly to plan – and there will always be new demands and requests to change the architecture. Phase H describes the change management process to manage changes to the architecture in a cohesive and architected way.
Typically this requires continual monitoring of governance requests, new technologies, or changes in the business environment.
The process should support the implemented enterprise architecture as a dynamic environment that has the flexibility to evolve rapidly in response to these changes.
In Phase H it is critical that the governance body set up criteria to judge whether a Change Request warrants a simple architecture update or whether it requires starting a new cycle of the Architecture Development Method (ADM). It’s important to avoid "creeping elegance", so changes must relate directly to business value!
How the enterprise architecture is used is the most important part of the architecture development cycle, so monitoring business growth and decline is critical in Phase H. Eventually the enterprise architecture that worked for the organization yesterday ceases to support the capabilities of today or tomorrow!
Change requests output from Phase H can be classified as simplification - often driven by a requirement to reduce investment; incremental change - driven by a requirement to derive additional value from existing investment; or rearchitecting change which is driven by a requirement to increase investment and create new value.
Enterprise Architecture TOGAF Video