Sequence flow
A process in the form of a sequence flow describes the sequence in which activities of a process are performed. The sequence flow combines the Event, Activity, and Gateway object types. Sequence flows are permitted only within pools and may not cross their borders (see the following figure).
The sequence flow is represented by a solid line with a black arrow head:
Appropriate connection types, such as activates, is evaluated by, creates, links, or leads to are specified depending on the connection's source and target object type.