Good question. The Change Mngt Plan and Config Plan could be part of the Develop Plan process. Both are closely related to Control Scope Process as they are an input there from Develop Project Mngt Plan. A Project Plan may or may not need these plans. The Develop Project Mngt Plan Process is kind of a basket and other plans more than likely will be developed and created before the Develop PMP Process is complete. Its my opinion, that yes its done there, but it may not be in a particular order.