1. Brief Description
2. Flow of Events

   2.1    Basic Flow - Create a Schedule

   2.2    Alternative Flows

                       2.2.1    Modify a Schedule

                       2.2.2    Delete a Schedule

                       2.2.3    Save a Schedule

                        2.2.4    Add Course Offering

                       2.2.5    Unfulfilled Prerequisites or Course Full

                       2.2.6    No Schedule Found

                       2.2.7    Course Catalog System Unavailable

                       2.2.8    Course Registration Closed

3. Special Requirements
4. Preconditions

   4.1    Login

5. Postconditions
6. Extension Points

    1.    Brief Description

This use case allows a Student to register for course offerings in the current semester. The Student can also modify or delete course selections if changes are made within the add/drop period at the beginning of the semester. The Course Catalog System provides a list of all the course offerings for the current semester.

The main actor of this use case is the Student. The Course Catalog System is an actor within the use case.

    2.    Flow of Events

The use case begins when the Student selects the "maintain schedule" activity from the Main Form.

2.1  Basic Flow - Create a Schedule

1. The Student selects "create schedule."
2. The system displays a blank schedule form.
3. The system retrieves a list of available course offerings from the Course Catalog System.
4. The Student selects 4 primary course offerings and 2 alternate course offerings from the list of available offerings. Once the selections are complete the Student selects "submit."
5. The "Add Course Offering" sub-flow is performed at this step for each selected course offering.
6. The system saves the schedule.

2.2  Alternative Flows

2.2.1    Modify a Schedule

1. The Student selects "modify schedule."
2. The system retrieves and displays the Student's current schedule (e.g., the schedule for the current semester).
3. The system retrieves a list of all the course offerings available for the current semester from the Course Catalog System. The system displays the list to the Student.
4. The Student can then modify the course selections by deleting and adding new courses. The Student selects the courses to add from the list of available courses. The Student also selects any course offerings to delete from the existing schedule. Once the edits are complete the Student selects "submit".
5. The "Add Course Offering" sub-flow is performed at this step for each selected course offering.
6. The system saves the schedule.

2.2.2    Delete a Schedule

1. The Student selects the "delete schedule" activity.
2. The system retrieves and displays the Student current schedule.
3. The Student selects "delete."
4. The system prompts the Student to verify the deletion.
5. The Student verifies the deletion.
6. The system deletes the schedule.

2.2.3    Save a Schedule

At any point, the Student may choose to save a schedule without submitting it by selecting "save". The current schedule is saved, but the student is not added to any of the selected course offerings. The course offerings are marked as "selected" in the schedule.

2.2.4    Add Course Offering

The system verifies that the Student has the necessary prerequisites and that the course offering is open. The system then adds the Student to the selected course offering. The course offering is marked as "enrolled in" in the schedule.

2.2.5    Unfulfilled Prerequisites or Course Full

If in the "Add Course" sub-flow the system determines that the Student has not satisfied the necessary prerequisites or that the selected course offering is full, an error message is displayed. The Student can either select a different course offering or cancel the operation, at which point the use case is restarted.

2.2.6     No Schedule Found

If in the "Modify a Schedule" or "Delete a Schedule" sub-flows the system is unable to retrieve the Student's schedule, an error message is displayed. The Student acknowledges the error and the use case is restarted.

2.2.7    Course Catalog System Unavailable

If, the system is unable to communicate with the Course Catalog System after a specified number of tries, the system will display an error message to the Student. The Student acknowledges the error message and the use case terminates.

2.2.8    Course Registration Closed

If, when the student selects "maintain schedule", registration for the current semester has been closed, a message is displayed to the Student and the use case terminates. Students cannot register for courses after registration for the current semester has been closed.

    3.    Special Requirements

There are no special requirements associated with this use case.

    4.    Preconditions

            4.1    Login

Before this use case begins the Student has logged onto the system.

    5.    Postconditions

There are no postconditions associated with this use case.

    6.    Extension Points

There are no extension points associated with this use case.