UML
> UML Example
The UML diagram examples below are all created in the case study of describing the QSIG
Private User Mobility Registration (PUMR) service in UML. Only a subset of the available
diagram notations in UML is used. The complete case study, as well as the methodology
for creating the UML models, is available in
EG 202 872
.
Use Case diagram
The creation of a use case model is an excellent vehicle for elicitation of functional
requirements. The activity consists of identifying use cases and actors and describing
the details of each use case.
The use case diagram above describes what services (use cases) that are available for different
categories of users (PUM user, Authorized user).
TOP
Sequence diagram
When describing the details of a use case (service), a sequence diagram is one of the
possible diagram kinds to choose from in UML. When making sequence diagrams, you focus
on describing the sequences of message interactions between communicating entities.
The sequence diagram above describes how the actor (PUM User) initiates the de-registration use case
and how the distributed system entities (Visitor, Home) interacts by message interchange in order to
carry out the service.
TOP
Activity diagram
Activity diagrams are another way to describe use case behaviour, focussing on how the behaviour can
be broken down in functions, internal to the system or system part.
The activity diagram above describes in what order different functions should be carried out
and, if they are optional, under what circumstances the functions should be invoked.
TOP
Class diagram
Class diagrams typically describe the different entities of a system as classes and the relation
between these. This may for example include
-
System parts and their relation
-
System data
-
Interfaces of communicating parts
-
Messages and operations of interfaces
The class diagram above describes the communicating entities of the PUMR model (Home PINX,
Visitor PINX, Directory PINX) and the interfaces with operations/messages that these entities
must realize.
The class diagram above shows the different setup messages of the PUMR model and the data these
messages carry.
TOP
Object diagram
The object diagram puts the classes in the class diagrams into context and shows how
individual instances of classes relate to each other.
The object diagram above describes how the communicating entities in the PUMR system environment
relate and the means for communication that exist.
TOP
|
