Creating an Activity

An activity is used to model how the software should realize a particular behavior by representing actions and their flow. An activity diagram describes precisely one non-trivial activity of a Behaviored Classifier.

Prerequisites

In order to be able to create an activity diagram, you need to specify the Behaviored Classifier for which the behavior is to be described. Behaviored classifiers include class, component and use case, among others.

Context

You can make the decision as to which behavior is to be described with the activity diagram in various ways:

Select a behaviored classifier and create an activity for it.
Create an activity from the ribbon without selecting, then make the selection in the following dialog. You can select an existing behaviored classifier from the dialog or create a new one.

How to proceed

To describe the behavior of an existing behaviored classifier as an activity, select the class, the component, the use case or the like and select Start>New>New Diagram>Activity.

The activity diagram is created and assigned to the behaviored classifier in the model structure as standard. The activity's owner is shown in the Details tool window.
To describe the behavior of an existing BehavioredClassifier – or one that is to be created – as an activity, select Start>New>New Diagram>Activity.

A selection dialog appears, prompting you to select a suitable behaviored classifier. Select an existing classifier or use the Create new element button to create a behaviored classifier that doesn't exist yet. In the latter case, a wizard will then take you through the necessary steps.

The activity diagram is created and assigned to the behaviored classifier in the model structure as standard. The activity's owner is shown in the Details tool window.