Flow charts are a required Systems Engineering tool for communicating a requirement or design. Here's an interesting and actually funny flow chart on the use of "Oh Snap"
Here's a more complicated, but still funny, that's been around for ages. The original was too vulgar for this family friendly site so I cleaned it up.
And of course the CLASSIC super complicated flow chart that destroyed the Neanderthals. Here's one of the conversations from one of the many Hunting Process Review (HPR) meetings they had.
I tell my students constantly, "If the process adds no value, then kill it!" Don't let the process get so complicated that it can't be implemented. As a Systems Engineer we are interested in satisfying our end users. Make sure the flow chart is not arbitrary but does add value.