Basic Description

Use case functionalities are described using a numbered list, each number describing one step performed by either the Actor or the System. Each step must start with the entity performing the action (either the actor, by name, or the system). This description should describe this use case as it should happen. Take, for example, Figure 3.1 and the following description in Figure 3.2.

Use Case: Place Order
Input: Customer details, Order details
Output: Confirmation
1. Customer goes to checkout
2. Customer fills in shipping information
3. System presents full order review
4. Customer fills in credit card information
5. System contacts bank to authorise transaction
6. System confirms sale
7. System sends confirmation email

In this example, even though it is a single use case, the actor and the system performed multiple actions. All of these actions are part of this single use case. However, everything will not always go as smoothly.