myassignmenthelp is leading assignment help provider for use case diagrams. whenever any one needs help with any diagram related assignments feel free to get in touch with us
2. Use Case Diagrams
โข In order to signify
external behavior
โข Actors signify functions,
that's, a kind of user of
the system
Passenger
PurchaseTicket
3. Use Case Diagrams
โข Use cases signify the
sequence associated with
interaction with regard to a
kind of functionality,
summary associated with
scenarios
โข The use case model may be
the set of all use cases. It's a
total explanation from the
functionality of the system
and its environment
Passenger
PurchaseTicket
4. Actors
โข An actor models an external entity that
convey using the system:
โ User
โ External system
โ Physical environment
โข An actor has a unique name as well as an
optional explanation.
โข For Examples:
โ Passenger: A person in the train
โ GPS satellite: Provides the system along
with GPS coordinates
Passenger
5. Use Case
The use case signifies the class of
associated with functionality supplied
by the actual system as an event flow.
The use case includes:
โข Unique name
โข Participating actors
โข Entry conditions
โข Flow associated with events
โข Exit problems
โข Unique needs
PurchaseTicket
6. Use Case Diagram: Example
Name: Purchase ticket
Participating actor: Passenger
Entry condition:
โข Passenger standing in front of
ticket distributor.
โข Passenger has sufficient money to
purchase ticket.
Exit condition:
โข Passenger has ticket.
Event flow:
1. Passenger selects the number of
zones to be traveled.
2. Distributor displays the amount
due.
3. Passenger inserts money, of at least
the amount due.
4. Distributor returns change.
5. Distributor issues ticket.
7. The <<extends>> Relationship
โข <<extends>> relationships signifies
exceptional or even seldom invoked
cases.
โข The exceptional event flows are
factored out of the main event flow
for clarity.
โข Use cases signifies exceptional flows
can extend more than one use case.
โข The actual path of the<<extends>>
relationship is to the extended use
case
Passenger
PurchaseTicket
TimeOut
<<extends>>
NoChange
<<extends>>OutOfOrder
<<extends>>
Cancel
<<extends>>
8. The <<includes>> Relationship
โข <<includes>> relationship
signifies behavior that's
factored from the use case.
โข <<includes>> is actually
factored away with regard to
reuse, not really since it is
definitely an exception.
โข The actual path of the
<<includes>> relationship
would be to the actual
utilizing use case (unlike
<<extends>> relationships).
Passenger
PurchaseSingleTicket
PurchaseMultiCard
NoChange
<<extends>>
Cancel
<<extends>>
<<includes>>
CollectMoney
<<includes>>
9. Use Cases are useful to
โข Identifying needs
โ New use cases usually create new specifications because
the system will be assessed as well as the layout will take
condition.
โข Interacting along with customers
โ Their notational simplicity can make use case diagrams a
good way with regard to developers to communicate with
clients.
โข Generating test cases
โ The collection of scenarios for a use case may suggest a
suite associated with test cases for those scenarios.
10. Use Case Diagrams: Summary
โข The use case diagrams symbolize external behavior
โข The use case diagrams are helpful because an
index to the use cases
โข The use case explanations supply meat associated
with model, not the use case diagrams.
โข All use cases need to being explained for the model
to be useful.