A sequence flow is an arrow that links flow objects. Sequence flows (along with gateways) show the order in which activities are performed in a process.
A sequence flow can be one of the following kinds:
Default
When multiple paths flow from a gateway, select the Default Flow check box to specify one of them as the default. The default path is taken only when no other path is valid.
Conditional
If you add a Boolean expression to the sequence flow’s Expression tab, the flow proceeds to the next task only if the expression evaluates to true.
Uncontrolled
A flow that is unaffected by conditions, and does not pass through a gateway. Can be used for simply connecting two activities, or can diverge from or converge to an activity, in parallel. (Similar to the lambda transition in a state model)
Note that the BPMN specification discusses additional types of flow. In TIBCO BusinessEvents Process Orchestration, various types of flow are selected internally based on context.
