How long did it take these three different fields to fully separate and have their own concentrations in universities? That may give us a timeline on how long it could be in the computer science, software engineering/architecture (does such a concentration exist involving architecture?), and software development methodology (project management... which is almost no existent in academia) fields.
Computer science used to be quite separate from application development and the nearest it would come to actual software was low level OS componentry. Any conglomeration is more recent.
