ITM 430 - Week 2
Type of Requirements:
Use Case: A text story of some actor using a system to meet goals.
Actor: is anything with behavior that triggers use case execution.
– Primary Actor accomplishes goals via use case
• Example: the cashier
– Secondary Actor provides a service to use case (often a computer system, but
could be an organization)
• Example: the automated payment authorization service
– Offstage actor is interested in use case results
• Example: government tax agency
Three possible use case formats:
• brief format: one paragraph summary usually of the main success scenario
Process Sale: A customer arrives at a checkout with items to purchase. The cashier
uses the POS system to record each purchased item. The system presents a running total and
a line-item details. The customer enters payment information, which the system validates and
records. The system updates inventory. The customer receives receipt from the system and
then leaves with the items.
• casual format: multiple parag