olemus
toiminguid, protsesse või tegevusi nooltega kujutav skeem
= a diagram showing sequence of events,
and their interconnectivity

näiteid
https://duckduckgo.com/?q=%22arrow+diagram&t=h_&iax=images&ia=images
https://www.projectmanager.com/blog/arrow-diagrams-activity-on-node-activity-on-arrow