How to name use cases and derive classes
346 views
Skip to first unread message
fatass
Dec 6, 2007, 2:12:08 AM12/6/07
to Xpdian UML Discussion Group
In modeling business use and platform independent use cases, a strong
case can be made for naming use cases with a verb and a noun. The verb
tells us what is done, while the noun tells us to what thing the verb
is done.
As such good use case names would be:
* Authorise user
* Create customer
* Update account
* And many more...
From this use case naming convention we can then very rapidly derive a
class diagram, where the noun of the use case becomes the class and
the verbs become operations on the classes.
An example can be seen here: http://groups.google.com/group/xpdian-uml/web/use-case-to-class-translation
case can be made for naming use cases with a verb and a noun. The verb
tells us what is done, while the noun tells us to what thing the verb
is done.
As such good use case names would be:
* Authorise user
* Create customer
* Update account
* And many more...
From this use case naming convention we can then very rapidly derive a
class diagram, where the noun of the use case becomes the class and
the verbs become operations on the classes.
An example can be seen here: http://groups.google.com/group/xpdian-uml/web/use-case-to-class-translation
Desmond Cargot
Dec 6, 2007, 9:47:08 AM12/6/07
to Xpdian UML Discussion Group
Certainly you will derive some classes by this naming
convention.However you may miss others. Also there may be a tendency
to define as a Use Case functionality that would be better expressed
as an operation on a class. e.g. Read Customer. Crash Car etc.
An alternative way of finding the classes (apart from a pure textual
analysis of a scenario given by a stakeholder) would be to create an
activity graph of a business work flow and derive classes, operations
and Use Cases from the work flow.
Just a thought
@_/"
convention.However you may miss others. Also there may be a tendency
to define as a Use Case functionality that would be better expressed
as an operation on a class. e.g. Read Customer. Crash Car etc.
An alternative way of finding the classes (apart from a pure textual
analysis of a scenario given by a stakeholder) would be to create an
activity graph of a business work flow and derive classes, operations
and Use Cases from the work flow.
Just a thought
@_/"
fatass
Dec 6, 2007, 10:00:14 AM12/6/07
to Xpdian UML Discussion Group
Absolutely!
Deriving the classes from the use case nouns is only the first step
towards building the class diagram. When the classes are defined in
this way, we still have to gather the requirements of the stakeholders
in terms of their information requirements. This may bring many more
classes to the fore. The next step would then to do a consistency
check against the existing use cases and to check if all classes are
referenced in a use case realization. If not, we may have to create
some additional use cases. In this way the use case model and the
class model may evolve together.
Regarding activity diagrams - I am in agreement with your proposal but
have another suggestion up my sleeve. Keep watching this space.
> > An example can be seen here:http://groups.google.com/group/xpdian-uml/web/use-case-to-class-trans...- Hide quoted text -
>
> - Show quoted text -
Deriving the classes from the use case nouns is only the first step
towards building the class diagram. When the classes are defined in
this way, we still have to gather the requirements of the stakeholders
in terms of their information requirements. This may bring many more
classes to the fore. The next step would then to do a consistency
check against the existing use cases and to check if all classes are
referenced in a use case realization. If not, we may have to create
some additional use cases. In this way the use case model and the
class model may evolve together.
Regarding activity diagrams - I am in agreement with your proposal but
have another suggestion up my sleeve. Keep watching this space.
>
> - Show quoted text -
Reply all
Reply to author
Forward
0 new messages