Write the flow of events and specify all fields for the use case UpdateTariff that you drew in Exercise 2–4. Do not forget to specify any relationships.

Question

Figure 2-2 depicts a possible solution for this exercise.
Use case name UpdateTariff
Participating actor Initiated by CentralComputerSystem
Flow of events 1. The CentralComputerSystem activates the “UpdateTariff” function of the ticket distributors available

on the network.

2. The ticket distributor disables the traveler interface and posts a sign indicating
that the ticket distributor is under maintenance.
3. The ticket distributor waits for the new database from the
CentralComputerSystem.

4. After waiting a minute for the ticket distributors to reach a waiting state, the CentralComputerSystem
broadcasts the new database.

5. The ticket distributor system receives the new database of tariff. Upon complete,
the ticket distributor sends an acknowledgement to the CentralComputerSystem.
6. After acknowledgment, the ticket distributor enables the traveler interface and
can issue tickets at the new tariff.

7. The CentralComputerSystem checks if all ticket distributors have acknowledged the new database. If
not, the CentralComputerSystem invokes the CheckNonRespondingDistributors use case.
Entry condition • The ticket distributor is connected to a network reachable by the CentralComputerSystem.
Exit condition • The ticket distributor can issue tickets under the new tariff, OR

• The ticket distributor is disabled and displays a sign denoting that it is under maintenance.

Quality
requirements

• The ticket distributor stays offline at most 2 minutes and is considered out-of-order otherwise.

Answer 1

use case UpdateTariff that you drew in Exercise 2–4. Do

not forget to specify any relationships.

Figure