Earlier quoted context omitted.
it's subtle, but "plan" (material resource planning, MRP) is essentially waterfall in this context, where you design first, then do work breakdown into a waterfall schedule. it suffers from cascading delays because of the bullwhip effect (among other things). it's project oriented (a 1-off, 1-time event). in contrast, "workflow" is akin to kanban in this context. you start with constraints (in this case time and mone…
I think what trips me up then is that "Plan" refers to a specific type of planning, I guess "MRP", but colloquially it would refer to anything that attempts to project how something will be done. Unfortunately I've had employers insist that planning in the colloquial sense was akin to waterfall and since we were agile it was verboten.
whether it's waterfall or agile shouldn't really matter. in agile, there is planning, but often it's workflow based (tracking flow via story points, or what not).