The earlier we detect them the easier it will be to avoid multiple
analyses, designs, and implementations. This will be particularly helpful later on;
otherwise there could be a risk that a desired change is not made to all fl ows
involved, causing the model to become inconsistent.
The essential description allows us to see the top level of our use case
fl ows and to start refactoring. Since the essential description does not contain any
technical aspects, we can discover even fl ows that are identical from the domain
perspective, and which differ only in their technical implementation.
Table 2.12 Summary: Non-redundant modeling of use cases.
Reference card: Model use cases without redundancies
Incoming and outgoing data
Use cases:
Services provided by the system.
Use cases [non-redundant]:
Use cases with generalization and include
relationships for non-redundant fl ow
description.
Motivation/description
Why? Redundant model information can cause serious problems if their consistency
is violated.
What? Identify common things between the use case fl ows and model these areas in
isolation to avoid redundancies.
Pages:
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202