Assignment #3
Due: Thurs, Feb 15, at the beginning of class
Objective
To gain practice in the notation of UML use case diagrams.
Task:
For this assignment, you will draw a use case diagram that illustrates the
use cases described for the case study below -- we will use the case study
of a voice mail system simulation (one of the examples of use case
descriptions shown during lecture class).
Details
Draw a UML Use Case diagram to represent the use cases in the case study
shown below.
- Each of the described use cases should be represented by a named use
case on the diagram
- Discover and add the appropriate actors to the diagram, along with the
appropriate associations (i.e. which actor(s) activate or communicate with
which use cases)
- Represent any appropriate relationships that may be present between
use cases (extend, include, and/or generalization)
- You may create extra use cases, if needed (to illustrate appropriate
relationships between cases, for example). Be sure to give any such use
cases appropriate names
Case Study: Voice Mail System
Here are a set of informally written use cases, describing the basic
intended functionality of the voice mail system. (Example comes from
Object Oriented Design & Patterns, Cay Horstmann, Wiley and Sons.)
Use Case: Reach an Extension
- The user dials the main number of the voice mail system.
- The voice mail system prompts the user to enter the mailbox
number, followed by #.
- The user types in the extension number of the message recipient.
- The voice mail system prompts user to leave a message now
Variation
- In Step 3, the user types an invalid extension number
- The voice mail system speaks an error message
- Continue with step 2
Use Case: Leave A Message
- The caller carries out Reach an Extension
- The caller speaks the message
- The caller hangs up
- The voice mail system places the recorded message in the recipient's
mailbox
Use Case: Log In
- The mailbox owner carries out Reach an Extension
- The mailbox owner types their passcode
- The voice mail system plays a mailbox menu (giving choices for the
following three use cases)
Use Case: Retrieve Messages
- The mailbox owner carries out Log In
- The mailbox owner selects "retrieve your messages" from menu
- The voice mail system gives another menu (message menu), with options
to (1) listen to current message, (2) save current message, (3) delete
current message, or (4) return to mailbox menu
- The mailbox owner selects the "listen" option
- The voice mail system plays the current message at the front of the
new message queue. (Note, this remains the "current" message until it is
saved or deleted).
- The voice mail system displays the message menu again
- User selects "delete" option. The message is permanently removed
- Continue with step 3
Variation (Saving a message)
- After step 6 above, user selects "Save" option instead. The message
is removed from the inbox (new message queue) and added to a "saved
message" queue
- Continue with step 3 above
Use Case: Change the Greeting
- The mailbox owner carries out Log In
- Mailbox owner selects "change greeting" menu option
- Mailbox owner speaks the greeting
- Mailbox owner presses # key to confirm
- Mail system sets the new greeting
Variation: Hang up before confirmation
- Start at step 3 above
- The mailbox owner hangs up the phone
- The mail system keeps the old greeting
Use Case: Change the Passcode
- The mailbox owner carries out Log In
- Mailbox owner selects "change passcode" menu option
- Mailbox owner dials new passcode
- Mailbox owner presses # key to confirm
- Mail system sets the new passcode
Variation: Hang up before confirmation
- Start at step 3 above
- The mailbox owner hangs up the phone
- The mail system keeps the old greeting
Submitting
- As with the previous assignment, you may use any drawing program or
CASE tool to do the drawing.
- Print out a hard copy of your diagrams, and hand them in by the due
date in class
- Make sure your name is on all pages handed in