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12.3.19 ControlFlow


   A control flow is an edge that starts an activity node after the previous one is finished.


    ActivityEdge (from BasicActivities , CompleteActivities , CompleteStructuredActivities , IntermediateActivities ) on page 338.


   Objects and data cannot pass along a control flow edge.


   No additional attributes


   No additional associations


   [1] Control flows may not have object nodes at either end, except for object nodes with control type.


   See semantics inherited from ActivityEdge . A control flow is an activity edge that only passes control tokens. Tokens offered by the source node are all offered to the target node.


   A control flow is notated by an arrowed line connecting two actions.

Figure 12.70 - Control flow notation


   The figure below depicts an example of the Fill Order action passing control to the Ship Order action. The activity edge between the two is a control flow, which indicates that when Fill Order is completed, Ship Order is invoked.

   Figure 12.71 - Control flow example

   Control flow is introduced to model the sequencing of behaviors that does not involve the flow of objects.

*Changes from previous UML

   Explicitly modeled control flows are new to activity modeling in UML 2.0. They replace the use of (state) Transition in UML 1.5 activity modeling. They replace control flows in UML 1.5 action model.