Calling an Operation of an Interaction Participant

To call an operation you use a special message type, the synchronous or asynchronous operation call.

Context

To call an operation, UML sequence diagrams use a special message type, the synchronous or asynchronous operation call.

For synchronous operation calls, you can create a return in the form of a reply message.

How to proceed

Select the vertical (dashed) part of the lifeline which the operation should be called from with the left mouse button.

The selected action is outlined with a blue frame and the carousel appears.
Move the mouse pointer over the message type Synchronous Call or Asynchronous Call.
With the left mouse button pressed, drag the icon toward the lifeline at which an operation is to be called.
Let go of the left mouse button over the lifeline you want to send the operation call to.

The Requirement dialog is opened and contains the operations already defined in your model.
Select an existing operation or use the Create new element button to create an operation that doesn't yet exist. In the latter case, a wizard will then take you through the necessary steps.
Confirm your selection with OK.

The operation call is created and labeled with the name of the called operation, including the name of all parameters of this operation.