Not sure if you’re talking about DRAKON here, but I love it for documentation of process flows.

It doesn’t really get complicated, but you can very quickly end up with drawings with very high square footage.

As a tool for planning, it’s not ideal, because “big-picture” is hard to see. As a user following a DRAKON chart though, it’s very, very simple and usable.

Link for the uninitiated: https://en.m.wikipedia.org/wiki/DRAKON