A capability is something a user or stakeholder needs to be able to do to achieve a goal or complete a task. It describes the ability, not the way it is provided. For example, booking a flight is a capability whether someone does it online or over the telephone. When a team jumps straight to an online feature, it may overlook other ways to meet the need. section 4.2.1
Work from the desired outcome toward the software:
- Identify the business goal and whose behavior could help achieve it. section 3.2.2
- Name the capability as an ability, such as being able to cope with an unexpected travel delay. section 3.2.2
- Choose features that could provide that ability, then use examples and User Stories to clarify and plan their delivery. section 4.2.1 section 5.2
Making membership renewal easier
A frequent-flyer team identifies the capability to let members renew their membership more easily. Online renewal and a notification when renewal is due are possible supporting features. Keeping the capability distinct from either feature lets the team discuss the member’s need and the business goal before committing to a particular piece of functionality. section 5.2.1
A feature is a tangible piece of functionality delivered to support a capability. Terminology can vary across teams: a product feature describes supported functionality, whereas a release feature describes new or modified functionality planned for delivery. Keep the underlying capability visible when discussing either. section 5.2.1 section 5.2.5
+ features
+ frequent_flyers
+ account
+ register.feature
+ change_password.feature
+ view_flight_history.feature
+ book_a_flight
+ book_with_points.feature
+ book_with_points_and_cash.feature
+ earn_points
+ earn_points_from_flights.feature
+ earn_points_from_hotel_stays.feature
+ earn_points_from_car_rentals.feature
This feature-file tree shows a practical way to preserve the relationship: group executable specifications by functional area and capability, so readers can find what the application supports. section 7.4.6
