Model Parts, Diagrams, Dictionary Items, and Properties > Dictionary items > Activity (dictionary item)
Activity (dictionary item)
For automation interface information about an Activity, see Activity (automation interface).
An Activity is a specification of parameterized behavior that is expressed as a flow of execution via a sequencing of subordinate units (whose primitive elements are individual actions).
Create an Activity from an Activity, Actor, Basic Type, Class, Interface, Model, Package, Operation, Type Definition and Use Case – right-click the owning item, point to New, and then click Activity. On a State Diagram, you can create an activity for a State through the Activity button.
Note that when you create an Activity from a Class or Interface, Modeler also creates an Activity Diagram as a child of the new Activity.
Describe the behavior of an Activity, or the parent item of the Activity, through an owned Activity Diagram.
If you want to create an Association between an Activity and a Class, you must do so through an Object Node. For more information, see Showing an association between an activity and a class on a class diagram.
When used on a Class Diagram, an Activity's notation is as follows.
For information about the View Options available for this symbol, see Activity view options - activity diagram and Activity view options - class diagram.
Note that when a Class Diagram shows an association or composite aggregation symbol starting from an Activity, that link symbol represents a Call Behavior Action, Central Buffer, Data Store, Input Pin or Output Pin, rather than an Association dictionary item. For more information, see the following topics:
Creating a composite aggregation between two activities on a class diagram
Showing an activity call tree on a class diagram
When you create an Activity Diagram from an Activity, the Activity is linked to the frame that is created on the diagram.
In the Modeler panes, a short-cut symbol on the Activity's icon indicates that the item is a stub. For more information, see Stubs.
You can specify the Parameters of an Activity through its signature. For more information, see Using an activity signature to specify name and parameters. If an Event's signature is greater than 200,000 characters, the Parameters' Default values are not included in the signature.
The following sections provide information about how an Activity is used in the model. For more information about a property, item, model part or diagram, click it.
In addition to the standard properties an Actor has these properties:
Read Only (Is Activity Read Only through the automation interface)
Reentrant (Is Reentrant through the automation interface)
Return Type (Data Type)
Single Execution (Is Single Execution through the automation interface)
Owned by
Basic Type
Type Definition
Use Case
Activity Diagram
Accept Event Action
Activity Final Node
Activity Partition
Add Structural Feature Value Action
Call Behavior Action
Call Operational Action
Central Buffer
Clear Association Action
Clear Structural Feature Action
Create Link Action
Create Object Action
Data Store
Decision Node
Destroy Link Action
Destroy Object Action
Flow Final Node
Fork Node
General Flow Diagram
Initial Node
Input Pin
Interruptible Activity Region
Join Node
Merge Node
Opaque Action
Output Pin
Read Extent Action
Read Link Action
Read Self Action
Read Structural Feature Action
Remove Structural Feature Value Action
Send Signal Action
Structured Activity Node
Test Identity Action
Value Specification Action
Defined in these parts of the model
Shown on these diagrams
Activity Diagram (attached to frame of child Activity Diagram only)
Class Diagram
General Flow Diagram
State Diagram (as an activity)
Variant Diagram
Can be linked to these dictionary items
Constraint – Constraints can be linked as Preconditions and Postconditions.
Operation – Operations can be linked as Specifications for the Activity.