Create a UML sequence diagram

Start a sequence diagram

1. Start Visio. Or if you have a file open already, select File > New.

2. In the Search box, type UML sequence.

3. Select the UML Sequence diagram.

4. In the dialog box, select the blank template or one of the three starter diagrams. (A description of each one is shown on the right when you select it.) Then select either Metric Units or US Units.

5. Select Create.

6. The diagram opens. You should see the Shapes window next to the diagram. If you don’t see it, go to View > Task Panes and make sure that Shapes is selected. If you still don’t see it, select the Expand the Shapes window button on the left.

7. On the View tab, make sure the check box next to Connection Points is selected. This option makes connection points appear when you start connecting shapes.

8. Now, drag shapes you want to include in your diagram from the Shapes window to the page. To rename text labels, double-click the labels.

Lifelines for actors and objects

Use an Actor lifeline shape for each participant, and an Object lifeline shape for each system component in your process.

• Double-click in the heading box for each lifeline to enter a name or title.

• To lengthen or shorten a timeline, select the lifeline, then drag the yellow control point at the bottom of the lifeline.

Messages

Use message shapes to represent information being sent between lifelines.

• Attach the beginning endpoint to the lifeline sending the message, then drag the head endpoint to the lifeline receiving the message.

• Double-click the message shape to create a text box, and type a name for the message.

• Use a Message shape (a solid line) to represent a request or the transmitting of information.

• Use a Return Message shape (a dashed line) to represent a response to a prior message.

• Use a Self Message to represent a recursive call of an operation, or one method calling another method belonging to the same object.

• Use the Asynchronous Message shape to show when an action might not happen immediately.

• To change the shape of a connector message:

  1. Right-click the connector.

  2. At the bottom of the pop-up menu, select from the three options (Right-Angle, Straight, Curved).

  3. Select and drag the connector to change its shape.

Fragments

If one or more interactions form a loop, or require a condition to be met to end the interaction, enclose those interactions in a fragment shape:

• Use the Loop fragment for a basic repeating interaction.

• Use the Optional fragment for steps that are only performed if a certain condition is met.

• Use the Alternative fragment shape for an if-then or if-then-else process or interaction. The fragment comes with two sections, which let you show the alternative interaction. To add another condition, drag an Interaction operand onto the shape. 

  

• Drag the fragment shape to the interactions it relates to. Use the sizing handles on the fragment shape to ensure it encloses all of the related interactions.

• Double-click in the title corner of the fragment shape to add a title or short description of the process enclosed by the fragment. Below the title corner, select the [parameters] prompt if you want to enter the conditions that would end that process.

Activation

Destruction

Destruction indicates when an object or actor is done participating in a system. A large X appears at the end of its lifeline. To show destruction of an object in a diagram:

• Right-click the object, and select Show Destruction.