There is always discussion about "Big Design Upfront," "Emergent Architecture," and other topics used either to explain why the world has gone wrong or be used as "red herrings" for a specific point of view.
Well if you want to see how architecture is used on programs that have "emergent" requirements, have evolving needs from the stakeholders, have changing and many times conflicting requirements, let's look at the V-Diagram.
By the way these programs would not be considered "agile" in traditional agile software development sense. These programs are complex weapons systems, space flight machines, large integrated work processes. Things Systems Engineers deal with every day.
This "vee" approach is at the heart of all systems engineering processes. Start with vague, but definable outcomes. The Mission and Vision statement type of outcomes. You know "fly to the moon, land, and return safely in my lifetime," type of mission and vision statements.
Then incrementally and iteratively develop the details at the next level, do the same for the design and test of these details. All along providing feedback to everyone involved to confirm we headed in the right direction.
This whole notion that "agile" software development is the counter to "water fall" is of course a red herring. The counter to "water fall" is not doing "water fall." It's not allowed in DoD 5000.02 except in special circumstances of full rate production. The Vee model of INCOSE is an approach suitable in a wide variety of domains, no just software. In fact software is embedded as a major component of nearly every major system today.
