Elaborated Use Cases

3.10 Elaborated Use Cases

After the derivation of the use case model, each use is elaborated by adding detail of interaction between the user and the software system. An elaborated use case has the following components:

• Use Case Name
• Implementation Priority: the relative implementation priority of the use case.
• Actors: names of the actors that use this use case.
• Summary: a brief description of the use case.
• Precondition: the condition that must be met before the use case can be invoked.
• Post-Condition: the state of the system after completion of the use case.
• Extend: the use case it extends, if any.
• Uses: the use case it uses, if any.
• Normal Course of Events: sequence of actions in the case of normal use.
• Alternative Path: deviations from the normal course.
• Exception: course of action in the case of some exceptional condition.
• Assumption: all the assumptions that have been taken for this use case.

As an example, the Delete Information use case is elaborated as follows:

Elaborated Use Case - Click to Enlarge

 
Use Case Name: Delete Information
Priority: 3
Actors: User
 
Summary: Deleting information allows the user to permanently remove information from the system. Deleting information is only possible when the information has not been used in the system

Preconditions: Information was previously saved to the system and a user needs to permanently delete the information.

Post-Conditions: The information is no longer available anywhere in the system.
 
Uses: Record Transactions, Cancel Action
 
Extends: None

Normal Course of Events:

1. The use case starts when the user wants to delete an entire set of information such as a user, commission plan, or group.
2. The user selects the set of information that he/she would like to delete and directs the system to delete the information. - Exception 1, 2
3. The system responds by asking the user to confirm deleting the information.
4. The user confirms deletion.
5. Alternative Path: Cancel Action
6. A system responds by deleting the information and notifying the user that the information was deleted from the system.
7. Uses: Record Transaction
8. This use case ends.

Alternative Path - The user does not confirm Deletion

1. If the user does not confirm deletion, the information does not delete.
2. Uses: Cancel Action

Exceptions:

1. The system will not allow a user to delete information that is being used in the system.
2. The system will not allow a user to delete another user that has subordinates.

Assumptions:

1. Deleting information covers a permanent deletion of an entire set of data such as a commission plan, user, group etc. Deleting a portion of an entire set constitutes modifying the set of data.
2. Deleted information is not retained in the system.
3. A user can only delete information that has not been used in the system.