Phase A provides a clear Statement of the Architecture Work that will be delivered in an iteration of the ADM. It also provides the Vision of the proposed enterprise architecture. This sense of direction is vital for guiding the work throughout this iteration of the ADM.
The Statement of Architecture Work defines the program of works to develop and deploy the architecture outlined in the Architecture Vision. And it is the Vision that provides the high level aspiration of the capabilities and business value that the proposed enterprise architecture will deliver.
Starting with the Request for Architecture Work, Phase A provides a tool (this Vision) that sells the benefits of the proposed capability to stakeholders and decision makers within the enterprise.
Business Scenarios are used to understand the business requirements and help articulate the architecture requirements implied by the required capability.
This is documented in the Statement of Architecture Work, which is used to build consensus to support the final architecture. Consensus is represented when the sponsoring organization signs this document.
The steps in Phase A are all about turning the Request for Architecture Work into a well articulated Statement for Architecture Work, and making sure that enterprise is able, ready, willing, and committed to make the necessary architectural changes.
This involves establishing the architecture project, including defining its scope, and confirming and elaborating architecture and business principles.
Phase A identifies the stakeholders and their concerns and requirements, and confirms business goals, drivers and constraints from the Preliminary Phase.
To ensure success, it also evaluates business capabilities, and assesses the readiness for business transformation, and addresses any transformation risks.Enterprise Architecture TOGAF Video