Looking at the basic tools to use for Mind Mapping and Project Management
Freeplane rather than Freemind
Freeplane Info - https://www.freeplane.org/wiki/index.php/Main_Page
Mindmeister - online and cost from 3 plus, has a combined package for Project Management called Meistertask
Trello could be an alternative for Task Management - there are Drupal Modules available - not tested
Mind mapping is a graphing technique that outlines concepts related to a central idea. The image shows relationships among pieces of the whole, from outward branches to specific ideas within them.
At the heart of mind mapping is simplicity. Creators are likely to make use of their entire space, using colors, images, and words to get their ideas across.
They were first popularized by Tony Buzan, an educational consultant focusing on creativity, memory, speed reading, and popular psychology, but the use of mind maps can be traced all the way back to Leonardo Da Vinci, Cassiodorus, and even Roman philosopher Anicius Manlius Severinus Boethius.
Project Management - https://www.youtube.com/watch?v=qkuUBcmmBpk
PM modules for Drupal are quite complex - CC tested a couple of them previously.