REQUIREMENTS GATHERING - A Developer's Guide to Data Modeling for SQL Server - page 106

Use Case Descriptions
A use case description is the basic document that outlines, at a high
level, the process that the use case describes. From the description you can
build a use case diagram that lays out the entire process (or set of
processes) associated with a system. The use case description generally
consists of all the information needed to build the use case diagram, but in
a text-based format. See Figure 5.1 for a sample use case description of a
process involving an operator booking a conference call for a customer.
This document contains several types of information. Let's break it
down into sections, field by field.

Overview information
The first six boxes describe what the use case documents, as well as
general administrative overhead for the document itself.
■

■

Use case name
This is the name of the specific use case being described. The
name should be the same on both the description document and
the use case diagram (which we discuss a bit later).

ID
This is a field that can be used to help correlate documents dur-
ing the design process.

■

Priority
In some scenarios, it may be necessary to prioritize use cases (and
their corresponding processes) to help determine the importance
of certain processes over others.

■

Principal
This is usually the trigger of the use case; it's generally a customer
(internal or external), another process, or a business-driven deci-
sion. This is the thing that causes the process documented by this
use case to be executed. (In some references, the principal is
called an actor .)

■

Use case type
There are two types of use cases and two levels of use cases.
Overview use cases contain very high-level, basic information
about a process. In contrast, detailed use cases contain as much
information as possible about the process. You can also classify use
cases by the type of information they contain. Essential use cases
contain information about the general steps executed within the
process, and real use cases describe the specific implementation

■