Via Harvard’s Project Zero & Making Thinking Visual comes Parts, Purpose, Complexities: a valuable and I think overlooked  Visible Thinking Routine that can be applied in a variety of ways (not just during a DEEP design thinking challenge).   As in any challenges there are parts to explore, flesh out and as well as figure out their purposes.  Where the fun begins is actually connecting the parts & purposes in relation to the challenge, the User, the end-result, the relationships within the challenge.  Do you ever stop to sketch out the many different layers to a challenge?   PPC is a great tool to help the designers slow-down and untangle all that has transpired during the process.