Use Case Properties

You can modify an object's properties from its property sheet. To open a use case property sheet, double-click its diagram symbol or its Browser entry in the Use Cases folder.

The General Tab contains the following properties:

Property	Description
Name	Specifies the name of the item, which should be clear and meaningful, and should convey the item's purpose to non-technical users.
Code	Specifies the technical name of the object, which is used for generating code or scripts
Comment	Descriptive comment for the object.
Stereotype	Extends the semantics of an object derived from existing objects but specific to your needs.

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, see "Specifying Diagrams as Related Diagrams" in Chapter 5, Diagrams, Matrices, and Symbols in the Core Features Guide.