This part of the TOGAF standard describes the initial phase of an architecture development cycle. It includes information about defining the scope of the architecture development initiative. Here, we identify the stakeholders and the goals. We create an Architecture Vision. This vision is approved and signed off. Based on this, we proceed with the further architecture development phases
Phase A is about project establishment and initiates an iteration of the architecture development cycle, setting the scope, constraints, and expectations for the iteration. It is required in order to validate the business context and to create the approved Statement of Architecture Work.
Note that the Preliminary phase creates a "Request for Architecture Work", whereas the Phase A creates a "Statement of Architecture Work". In Preliminary phase, we identify the scope of the enterprise impacted by the architecture. Here, we identify the scope of the architecture itself.
The objective of the Phase A is to develop a high-level aspirational vision. Here, we create a vision of the capabilities and business value - that should be delivered as a result of the proposed Enterprise Architecture. Based on this, we generate an approved Statement of Architecture Work. This defines a program of works to develop and deploy the architecture outlined in the Architecture Vision.
The way to go with this phase is to follow these steps. Contrary to the Preliminary Phase, These steps are focused on the particular iteration of the ADM rather than the entire enterprise project.
The Architecture Vision Phase can follow directly after the Preliminary Phase, or after a complete iteration on entire circle. Thus, the inputs to this phase come from the outputs of the preliminary phase or those of the previous ADM cycle, or the enterprise requirements.
Based on the inputs, the Phase A generates an architecture vision for that ADM cycle. This includes:
Along with these, the Phase A also generates the basic template drafts for the eight architecture definition documents to be produced in the following phases:
With the vision laid out, we are now ready to go ahead and populate each of these eight architecture documents.