ProductsUModelUML Use Case Diagrams

Use case diagrams are the starting point for UML-based software development projects. As you draw your first use case, you will immediately experience the user-friendly flexibility of Altova UModel® 2012.

UML use case diagrams describe the interaction of any person or external device with the system under design. Use cases are often developed in collaborations between software developers and other project stakeholders, such as users of the proposed system, who will not go on to perform the actual coding.

Altova UModel Features Overview

Altova UModel® 2012 is an intuitive, affordable, and fully featured tool to create UML use cases, and to enjoy all the additional advantages of UML-based software development. UModel supports these advanced features:

• All 14 UML diagram types, plus a UML-style diagram for XML Schemas, and business process (BPMN) modeling
• Generate application source code in Java, C#, and Visual Basic languages
• Reverse engineer existing Java, C#, and Visual Basic applications
• XMI 2.1 interchange standard for UML models
• Support for Model Driven Architecture
• Automatically generate comprehensive, customizable project documentation
• Tight integration with Visual Studio and Eclipse
• And much more . . .

 Click here to download a fully functional, free 30-day trial of Altova® UModel® 2012!

Creating Use Case Diagrams with Altova UModel

There are two basic elements used in UML use case diagrams: the ellipse (or oval shape) and the actor. The ellipse contains a description of the specific interaction an actor may perform with the system under design. Additionally, it is sometimes used to represent subsequent system relationships. The actor characterizes the interacting person or thing.

Click image to enlarge use case tool screenshot

You can create your use case ellipse from the toolbar or the right-click context menu. Either way, you will see entry helpers, fast editing buttons, and element characteristics to assist you. UModel® 2012 even automatically selects the name field so you can just start typing your own description. The ellipse will autosize to fit your identifier, or you can click and drag at any time to manually resize it.

Click image to enlarge use case tool screenshot

Cascading styles permit you to change the fill color for use case ellipses either individually, in groups, or throughout the project. You can draw your own generalization, association, include, and extend relationship lines and position them manually by selecting from the use case toolbar, or you can grab the entry helpers that surround the ellipses. UModel® 2012 features fast editing buttons and specialized entry helpers for each supported UML diagram type. Roll your cursor over any helper or button to view a tool tip!

When you go back later to revise your UModel® 2012 use case diagram, the entry helpers and fast editing buttons reappear as you select the ellipse (or any other diagram element) again.

Along with the ellipse, the other major element of a use case diagram is the actor that interacts with the system. The traditional UML stick figure actor, descended from whiteboard brainstorming sessions, is simple to draw by hand, but alone, the basic stick figure is deficient in a modern UML application.

• The traditional stick figure does not scale well.
• The traditional stick figure does not accurately represent non-human actors. For instance, if your project is an auto navigation system, one of your actors might be a GPS satellite.
• The traditional stick figure does not visually differentiate the roles of various human actors such as a customer, a shipping clerk, or a payroll manager.
• The traditional stick figure could make an impression on non-programmers that your problem analysis is primitive, when it is actually very thorough.

Click image to enlarge use case tool screenshot

Enhanced Images for Use Case Actors

UModel® 2012 introduces a new stick figure that can scale horizontally or vertically without forcing your actor to do calisthenics or a dancer’s split. Alternatively, UModel® 2012 lets you assign your own images as symbols for your actors. You can use any of the images in the extensive library provided with UModel® 2012 or build your own set of .bmp illustrations to represent the various human roles or devices that are actors in your projects.

Click image to enlarge use case tool screenshot

UModel® 2012 customized actors enhance your use case diagrams on screen and in printed documentation.

Hyperlink Use Cases to URLs, External Files, or Other Diagrams

You can create hyperlinks from use case diagrams to external files, to Web addresses, or to other diagrams in your project. For instance, you might want to add a hyperlink to your use case oval that references a sequence diagram.

Clicking the hyperlink in the use case conveniently opens the sequence diagram to document implementation of that project requirement.

SysML Use Case Diagrams

UModel also supports SysML use case diagrams, which extend UML use case diagrams by adding the SysML allocate element. Click here to read more about support for SysML in UModel® 2012.

Draw accurate and attractive use case diagrams with UModel® 2012 to communicate more effectively with other developers and project stakeholders. Click here to download a free 30-day trial of Altova UModel® 2012 today!