extension | has definition A use case that makes optional interactions explicit or handles exceptional cases | ![2001-08-30 14:55:33.0](facet.gif) |
has purpose to make optional interactions explicit or to handle exceptional cases, therefore allowing the description of the basic use case to remain simple | ![2001-08-30 14:55:33.0](facet.gif) |
is a subtopic of 7.3 - Developing Use Case Models of Systems | ![2001-08-30 14:55:34.0](facet.gif) |
is related to the use case it extends | ![2001-08-30 14:55:34.0](facet.gif) |
is a kind of use case | ![2001-08-30 14:55:34.0](facet.gif) |
lists all the steps from the beginning of the use case to the end, including the handling of the unusual situation | ![2001-08-30 14:55:34.0](facet.gif) |
use case | assists an architect with the first draft of the architectural model | ![2001-08-30 14:58:12.0](facet.gif) |
can be used to plan the development process | ![2001-08-30 14:58:12.0](facet.gif) |
can be used to structure user manuals | ![2001-08-30 14:58:12.0](facet.gif) |
can form the basis for the definition of test cases | ![2001-08-30 14:58:12.0](facet.gif) |
can serve as as part of the contract between the customers and the developer | ![2001-08-30 14:58:12.0](facet.gif) |
describes the user's interaction with the system | ![2001-08-30 14:58:12.0](facet.gif) |
does not describe the computations the system performs | ![2001-08-30 14:58:12.0](facet.gif) |
give an architect an idea about which components will be needed and how they will interact | ![2001-08-30 14:58:12.0](facet.gif) |
has a use case name | ![2001-08-30 14:58:12.0](facet.gif) |
has actors the actors or actor who can perform this use case (optional) | ![2001-08-30 14:58:12.0](facet.gif) |
has goals zero or more goals | ![2001-08-30 14:58:12.0](facet.gif) |
has postconditions zero or more postconditions | ![2001-08-30 14:58:12.0](facet.gif) |
has preconditions zero or more preconditions which describe the state of the system before the use case occurs | ![2001-08-30 14:58:12.0](facet.gif) |
has related use cases zero or more use cases that may be generalizations, specializations, extensions or inclusions of this one | ![2001-08-30 14:58:12.0](facet.gif) |
has steps each step of the use case using a two column format, with the left column showing the actions taken by the actor, and the right column showing the system responses | ![2001-08-30 14:58:12.0](facet.gif) |
has summary | ![2001-08-30 14:58:12.0](facet.gif) |
includes only actions in which the actor interacts with the computer | ![2001-08-30 14:58:12.0](facet.gif) |
is used to develop requirements | ![2001-08-30 14:58:12.0](facet.gif) |
is used to validate requirements | ![2001-08-30 14:58:12.0](facet.gif) |
may have high political or commercial value | ![2001-08-30 14:58:12.0](facet.gif) |
may have one or more preconditions | ![2001-08-30 14:58:12.0](facet.gif) |
may represent a high risk because for some reason their implementation is problematic. | ![2001-08-30 14:58:12.0](facet.gif) |
must be validated using requirements validation methods | ![2001-08-30 14:58:12.0](facet.gif) |
normally includes only actions in which the actor interacts with the system | ![2001-08-30 14:58:12.0](facet.gif) |
should be independent of any particular user interface design | ![2001-08-30 14:58:12.0](facet.gif) |