UML Modeling Techniques > Object interaction modeling > Sequence diagram > Objects > Adding objects to a sequence diagram
  
Adding objects to a sequence diagram
You add objects along the top of the Sequence Diagrams:
Actors must be added to the left of the System Boundary.
Instances, Parts and Ports can be added to the left or right of the System Boundary.
Interface Devices, Packages and Subsystems must be added to the right of the System Boundary.
You can add Ports to a Sequence Diagram only by dragging them from an appropriate pane. Use the Parts pane to view Ports in context. On a Class or Interface owned Sequence Diagram, you can create Parts on the owning Class or Interface through the diagram.
To add objects to a sequence diagram:
1. Open the Sequence Diagram.
2. Click the appropriate toolbar button:
Actor
Instance
Interface Device
Package
Part
Subsystem
3. To add a new item to the Sequence Diagram:
Click the Sequence Diagram in an appropriate place.
To add an existing item to the Sequence Diagram:
a. Right-click the Sequence Diagram in an appropriate place.
b. Select the required item, and then click OK.
Modeler adds the item to the diagram.
Alternatively:
Drag an item from an appropriate pane to the diagram.
For a Class or Interface owned Sequence Diagram, you can drag a Class, Data Type, Interface or Signal to the diagram and Modeler will create a Part on the owning Class or Interface that uses the dragged item as its type.
Note that when you create a Part: if the Part is untyped, Modeler creates and Attribute; if the Part is typed, Modeler creates a Role.