Traditional, plan-driven processes are typically derived from the waterfall-model. This means there is a dedicated design phase and a subsequent implementation phase. The number of phases, the degree of design documentation, the produced artifacts, etc. may vary but the essential way of thinking is that design always precedes implementation.
Depending on how detailed the design phase is, there may still be some design decisions left to the implementation phase. The one extreme case would be that only the coarse-grained architecture is designed in the design phase leaving everything else to implementation. And the other extreme would be that absolutely everything is designed upfront so that implementation is only a manual task transforming the specification into program code.
The typical generative approach used here is the Booch method or something similar. This means the reality is modeled and this object model of reality is gradually transferred to an executable program. The principle directly corresponding to that idea is the MP. So in many cases the starting principle will be MP. Depending on the given design problem sometimes another principle is the more obvious start. But in plan-driven approaches there is a tendency for MP.