The Project Management Plan as you say includes all the sub-plans, tools and techniques, etc.
The Project Management System is a way of using the tools and techniques to manage the plan, for instance Microsoft Project is a type of Project Management System, although incomplete for a whole system, it can help you manage your schedule, and costs. The system is a tool, so can be part of the plan, by the plan is never part of the system.
Moderators: Yolanda Mabutas, Ahmed Amin, Scott Gillard, Mary Kathrine Padua, ERIC BARTLETT, Gail Freedman, Kevin Nason, Steven Mudrinich, PMP, Mark Wuenscher, PMP, John Wolverton, Tracy Shagnea, PMP, Jada Garrett
This interview with Simona Fallavollita (LinkedIn Profile) was recorded at the magnificient Project Management Institute (PMI)® Global Conference 2017 in Chicago, Illinois. We discuss the how, what, why and when of the changes that are coming to the PMP exam.