Universal Process Notation (UPN) is another business process modeling format. It’s simpler than BPMN and it has been adopted by Salesforce which means that it’s very popular in my world.
I would love to see a standard library to support UPN. Here’s a few resources that describe how it works. It uses only a couple of shapes with some special behaviors.
Resources explaining UPN:
https://unitfly.com/insights/what-is-universal-process-notation-upn/
https://www.techtarget.com/searchcio/definition/Universal-Process-Notation-UPN#:~:text=UPN%20was%20developed%20in%20the,Software%20acquired%20Nimbus%20in%202011.)
https://elements.cloud/blog/upn/