The Business Analyst is the gatekeeper of what is in scope for each release. As releases should be infrequent (we suggest one every eighteen months), making sure everything that is important to go live in the next three releases is detailed up front.
It is the analyst’s job to meet with all stakeholders and provide detail for all the new features in the release. It is well know that cost of changes increases the later they are identified in the software development process, so it is very important for the analyst to polish the specifications to perfection for all features, and to guard against attempts to change anything in the resulting requirements list and documentation later on.
This requirements list and documentation is duly signed by project stakeholders, and taken to the projects Architect. In the following three months (suggested) the Architect defines the architecture that will be developed to deliver everything listed. The artifacts for this exercise are diagrams, documents describing the structure, and a list of hardware and software to purchase for development, and closer to go-live, production.
Many projects print a limited number of bound books for the architectural designs, and posters to pin up for some of the diagrams.