Using the activity diagram in Figure 9.8 and the sequence diagrams in Figures 9.7 and 9.9, list the steps of other scenarios that can occur in the “make sale” use case. Diagram some of these scenarios as sequence diagrams. (Hint: There will be eight additional scenarios.)

The theater is considering a change in its policy that all sales are final. In particular, it is going to allow cancellations of a sale up to 24 hours after a sale is made. The customer requests a cancellation by submitting the Sale Transaction ID, name, and address on the cancellation page of the Web form. The system interrogates the database to confirm the information and that the transaction is less than 24 hours old. If true, the system asks the customer to confirm that he or she wants to cancel the sale. If the customer confirms the cancellation, the MasterCard account is credited and the Status attribute of the Sale object is changed from Active to Canceled. The system confirms to the customer that the sale has been canceled. Also, the Ticket object status changes from “committed” to “available.” The cancellation of a sale requires crediting the MasterCard (reversing the debit) and writing a cancellation to the Sale and Ticket objects. All tickets involved in the sale become uncommitted when the sale is canceled.

(a) Write a text description of a “normal” scenario for the “Cancel sale” use case.

(b) From the scenario, create a sequence diagram at the level of detail shown in Figure 9.6.

(c) Create an activity diagram. Include other logical scenarios in the activity diagram.

(d) Revise the ticket object’s state chart diagram (Figure 9.11) to include the new use case.

(e) Create a new state chart showing the behavior of the Sale object.

(f) Update the class diagram (Figure 9.21) to include the new attributes and methods required for this use case.