In trying to connect my experience in software engineering with the enterprise architecture world I work in these days, I thought I'd record an epiphany about divergent meanings of architecture in those two worlds.
I've struggled to understand architecture in relation to software construction; as an early stage in the design-implement-build waterfall. I could never see how a set of accounting categories could be of the slightest use to building a software system. The only point of connection is that the categories can be used to justify the funding based on expected performance improvements, and without funding construction doesn't begin.
Ultimately I realized that it has (at least) two entirely different meanings that don't connect other than in the remote sense that funding connects to construction. The epiphany was that (and I'm inferring this; I know of no historical records to back this up) that the meaning in Enterprise Architecture emerged when some influential accountant realized that the categories of an enterprises' budget reflects the "architecture" of that enterprise. "Enterprise Architecture" caught on to mean a set of budgetary categories. This is certainly the main meaning used in OMB/GAO and the Department of Defense at least. In other words, the benefit that EA brings to construction isn't a top-level systems design; the benefit is the funds to begin design, which occurs from a nearly clean slate.
The other meaning, the one I've used elsewhere in this blog, is the meanings of architecture from construction industries. It applies after funding has been settled but before construction begins. Its a dialog between architect and customer that occurs before construction crews start work but well after the financing has been arranged. Of course these budgetary categories have no relevance to the architects, designers and builders actually doing the work. They do help to round up the funding but thatt goes on in an entirely different world before these roles even enter the field.
The astonishment was how little these two meanings have in common, and that such a vast difference is simply taken for granted and not more explicitly spelled out.