Understanding Workflows

Each activity represents the performance of a group of actions in a workflow. Once the activity is complete, the flow of control moves to the next activity or state through a transition. If an outgoing transition is not clearly triggered by an event, then it is triggered by the completion of the contained actions inside the activity. A unique activity diagram feature is a swimlane that defines who or what is responsible for carrying out the activity or state. It is also possible to place objects on activity diagrams. The workflow stops when a transition reaches an end state.

You can attach activity diagrams to most model elements in the use case or logical views. Activity diagrams cannot reside within the component view.

You can use the following tools on the activity diagram toolbox to model activity diagrams:

Decisions	States
Swimlanes	Synchronizations
Objects	Transitions
Object flows	Start state
Activities	End state

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Creating an Activity Diagram

You can create activity diagrams on most model elements except for attributes, associations, or model elements that appear in the component view.

To create an activity diagram:

1 In the browser, right-click any model element except for attributes, associations, or model elements that appear in the component view.

2 Click New > Activity Diagram.

3 Rename or double-click to display the NewDiagram icon in the browser.

Another way to create an activity diagram:

1 Click the Browse State Machine Diagram button from the toolbar.

2 Click New.

3 Select the Activity Diagram check box in the New State Machine dialog box.

4 Enter the activity diagram title.

5 Click OK.

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Workflow Modeling

In business and in other industries, there are many manual and automated systems. Each of these systems contains one or more workflows. A workflow is best defined as a well-defined sequence of activities that produces an observable value or objective to an individual or entity when performed. You can model workflows with activity diagrams.