Use Case Properties

To view or edit a use case's properties, double-click its diagram symbol or Browser or list entry. The property sheet tabs and fields listed here are those available by default, before any customization of the interface by you or an administrator.

The General tab contains the following properties:
Property Description

Name/Code/Comment

Identify the object. The name should clearly convey the object's purpose to non-technical users, while the code, which is used for generating code or scripts, may be abbreviated, and should not normally include spaces. You can optionally add a comment to provide more detailed information about the object. By default the code is generated from the name by applying the naming conventions specified in the model options. To decouple name-code synchronization, click to release the = button to the right of the Code field.

Stereotype

Extends the semantics of the object beyond the core UML definition. You can enter a stereotype directly in this field, or add stereotypes to the list by specifying them in an extension file.

Keywords

Provide a way of loosely grouping objects through tagging. To enter multiple keywords, separate them with commas.

Specification Tab

The Specification tab contains the following properties, available on sub-tabs at the bottom of the dialog:

Property

Description

Action Steps

Specifies a textual description of the normal sequence of actions associated with a use case.

For example, the action steps for a use case called 'register patient' in a hospital might be as follows: "Open a file, give a new registration number, write down medical treatment".

Extension Points

Specifies a textual description of actions that extend the normal sequence of actions. Extensions are usually introduced with an "if ....then" statement.

For example, an extension to the action steps above might be: "If the patient already has a registration number, then retrieve his personal file".

Exceptions

Specifies signals raised in response to errors during system execution.

Pre-Conditions

Specifies constraints that must be true for an operation to be invoked.

Post-Conditions

Specifies constraints that must be true for an operation to exit correctly.

Implementation Classes Tab

A use case is generally a task or service, represented as a verb. When analyzing what a use case must do, you can identify the classes and interfaces that need to be created to fulfill the task, and attach them to the use case. The Implementation Classes tab lists the classes and interfaces used to implement a use case. The following tools are available:

Tool

Action

Add Objects – Opens a dialog box to select any class or interface in the model to implement the use case.

Create a New Class – Creates a new class to implement the use case.

Create a New Interface - Creates a new interface to implement the use case.

For example, a use case Ship product by express mail could be implemented by the classes Shipping, Product, and Billing.

Related Diagrams Tab

The Related Diagrams tab lists diagrams that help you to further understand the use case. Click the Add Objects tool to add diagrams to the list from any model open in the workspace. For more information, Core Features Guide > Modeling with PowerDesigner > Diagrams, Matrices, and Symbols > Diagrams > Specifying Diagrams as Related Diagrams.