Activity modeling is achieved through Activities, their Activity Diagrams and the items that appear on those diagrams.

When you want to describe the behavior of an item through an Activity you create that Activity as a child item of the item you want to describe. From the Activity you can then create one or more Activity Diagrams to model the behavior of the item that owns the Activity.

You can create all the Activity model item types on an Activity Diagram. Alternatively, you can create all the Activity model items except for the flows through an Activity in a Modeler pane: right-click the Activity, select New, and then click the appropriate submenu and command.

You create an Activity as a child of an item you want to describe through that Activity and its Activity Diagrams. You can create an Activity as a child item of the following item types: Activity, Actor, Basic Type, Class, Interface, Model, Package, Operation, Type Definition and Use Case.

Activities can also be created through Class Diagrams. On a Class Diagram:

For more information about Activities, see the following topics:

Activity Diagrams allow you to model the behavior of an Activity.

An Activity Diagram can be created only from an Activity: right-click the Activity, select New > Activity Diagram.

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:

All Activity Diagram items must be within the frame, which you can stretch to make bigger.

Like other diagrams, you can drag valid items from a Modeler pane to an Activity Diagram, and add valid items by clicking an Activity Diagram button, and then right-clicking an Activity Diagram.

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.

For more information about Activity Diagrams, see the following topics:

The following item types are activity group items:

The activity group items allow you to group and organize other Activity Diagram items.

An Interruptible Activity Region does not own the items it contains on an Activity Diagram; the items are owned by the Activity that owns the Activity Diagram.

A Structured Activity Node owns any items it contains on the Activity Diagram. Structured Activity Nodes can own other Structured Activity Nodes.

An Activity Partition does not own the items it contains on an Activity Diagram, but an Activity Partition can own other Activity Partitions. An Activity Partition typically represents a Modeler item - adding an item to an Activity Partition signifies a relationship between that item and the item that is represented by the Activity Partition.

An Activity Partition's view options allow you to orientate a group of Activity Partitions vertically or horizontally.

For more information about activity group items, see the following topics:

The following item types are activity node items:

When you create an action node item that has a Linked Item, you are prompted to select or create that Linked Item. You cannot change an action node item's Linked Item after creation. On some action node items, you can show a Linked Item's Parameters or Attributes as Input Pins and Output Pins. You can create the following action node items by dragging an Activity, Event, Operation or Signal to an Activity Diagram; the dragged item is set up as the Linked Item of the action node item:

Unlike the other action node items, for Opaque Actions you can specify Body and Language property values.

On an Activity Diagram, you can double-click an action node to open child diagrams of the linked item.

For information about pins on action node items, see the Object Node Items section that follows.

For more information, check the related topics about activity node items.

The following item types are object node items:

Object node items have Data Types, Ordering and Multiplicity properties. In addition, they can be linked to States that are available to the object node item.

You can create Input Pins and Output Pins on the following items: diagram frame (the owning Activity), Structured Activity Nodes, Accept Event Actions, Call Behavior Actions, Call Operation Actions, Opaque Actions and Send Signal Actions. When creating an Input Pin or Output Pin on an item, ensure that you click the edge of the item.

When you create an Input Pin or Output Pin on an Activity Diagram, a popup menu allows you to add an existing Input Pin or Output Pin, or create a new Input Pin or Output Pin.

The following example shows the popup menu that appears when adding an Input Pin to a Call Behavior Action. You can see that the popup menu allows you to add an existing Input Pin to the symbol (Parameter1 or Parameter2 commands), create a new Pin for an existing Parameter (Parameter3 command), or create a new Input Pin and a new Parameter (New Parameter command).

When a symbol's Input Pin or Output Pins are not shown on the diagram, you can add them to the diagram through that item's context menu: right-click the edge of the symbol, point to Add, and then click Input Pin or Output Pin.

The type of the symbol that owns the Input Pin or Output Pin determines what the Input Pin or Output Pin represents. The following table shows you what the Input Pins and Output Pins can represent, that is, what their Linked Item is.

Modeler typically ensures that the name of an Input Pin or Output Pin matches the name of its linked item:

You can populate Input Pins and Output Pins on an Activity Diagram: right-click an Activity Diagram item, and select Populate > Pins.

For more information about object node items, see the following topics:

The following item types are control node items:

Control node items allow you to control the flow of Control Flows and Object Flows.

The Join Node has Join Specification and Combine Duplicate properties, and the Decision Node has a Behavior property.

Orientate a Fork Node or Join Node horizontally or vertically through its View Options.

For more information about control node items, see the following topics:

The following item types are activity flow items:

Activity Flow items specify connections along which tokens flow between activity node items.

Activity Flow items have Guard and Weight properties; Exception Handlers has an Exception Type property; Object Flows have Multicast, Multireceive, Selection and Transformation properties.

The following table shows you what can be the source and destination items for Control Flows, Exception Handlers and Object Flows on an Activity Diagram.

For more information about activity flow items, see the following topics: