[tootie]

Maybe I'm nuts because I've never found these useful. If you actually want to model a real-world scenario, you'll end with an arrow from every system to every other system to the point that it's meaningless as a visualization.

[bnjms]

I think you’re nuts :) I find them super helpful for refreshing when I need to see the flow for protocol exchanges like SIP, FTP, TLS.

I don’t know how else you would model that. Words don’t communicate deeply enough.

[tootie]

I'm thinking more about business processes rather than protocols. I don't think most project involve devising new protocols. If I want to diagram the steps involved in, say, onboarding and nurturing a user, then the flow will rapidly approach a cyclic, undirected graph.