Activity diagram

Model Parts, Diagrams, Dictionary Items, and Properties > Diagrams > Activity diagram

Activity diagram

Activity Diagrams can be used to model the sequence and conditions for coordinating lower-level behaviors of an Activity through activity group, action node, object node, control node and activity flow items.

You create an Activity Diagram through the context menu of an Activity:

• Right-click the Activity, and select New > Activity Diagram.

When the UML Profile is present in the Model, you can create an Activity Diagram from an Actor, Class or Use Case (Modeler creates an Activity to own the Activity Diagram):

• Right-click an Actor, Class or Use Case, and select New > UML > Activity Diagram (from an Activity).

When you create an Activity from a Class or Interface, Modeler also creates an Activity Diagram as a child of the new Activity.

When you create an Activity Diagram, Modeler creates a frame that is linked to the owning Activity. Modeler creates the following Input Pins and Output Pins on the frame:

• If the owning Activity has a return type, Modeler creates an Output Pin on the frame named Return Pin.

• If the owning Activity has parameters, Modeler creates Input Pins and Output Pins to represent those Parameters.

On an Activity Diagram, all Activity Diagram items must be within the frame.

When you create items on an Activity Diagram, those items are created as child items of the Activity that owns the Activity Diagram, unless you create the item on a Structured Activity Node, in which case the item is scoped to the Structured Activity Node. Items can appear on an Activity Diagram only if they are child items of the Activity that owns the Activity Diagram.

On an Activity Diagram, when you create an item in or move an item to a Structured Activity Node, that item is scoped to the Structured Activity Node. If an item is scoped to a Structured Activity Node and you move that item to the diagram background or to another Structured Activity Node, the item is rescope accordingly.

Item Group	Activity Diagram Item
Activity group items	Activity Partition Interruptible Activity Region Structured Activity Node
Action node items	Accept Event Action Add Structural Feature Value Action Call Behavior Action Call Operation Action Clear Association Action Clear Structural Feature Action Create Link Action Create Object Action Destroy Link Action Destroy Object Action Opaque Action Read Extent Action Read Link Action Read Self Action Read Structural Feature Action Remove Structural Feature Value Action Send Signal Action Test Identity Action Value Specification Action
Object node items	Central Buffer Data Store Input Pin Output Pin
Control node items	Activity Final Node Decision Node Flow Final Node Fork Node Initial Node Join Node Merge Node
Activity flow items	Control Flow Exception Handler Object Flow

You must use an Activity Diagram to create the following Model items:

Control Flow

Exception Handler

Object Flow

If you want to explore the relationships between the items that appear on Activity Diagrams, you may find it useful to see the Activity Model section on the Relationships pane.

The following sections provide information about how an Activity Diagram is used in the model. For more information about an item, property or model part, click it.

Shows these dictionary items

Like most diagrams, an Activity Diagram can show variability items and relationships. See Overview of variability items and relationships on diagrams.

For most diagram symbols, you can change the presentation of the symbol through the Style view options ( tell me more...), and change the showing of Stereotypes and Tag Definitions through the Stereotypes view options (See Stereotypes view options for a symbol - all diagrams). When a symbol has additional view options for changing its presentation, this icon