Why is all of this important, you may ask? The answer is quite simple.

Advantages

·         They prevent early design and focus on conditions.

·         They provide tractability.

·         They allow estimating and scheduling work.

·         They are easy to understand by the client, and provide a simple means of communication between the client and the developers.

Disadvantages

·         They do not easily capture non-functional requirements.

·         There may be a learning curve for the developer and/or the client.

In summary, a well-prepared use case is worth its weight in gold. Once the client has agreed with the use case, project managers can plan the schedule, and developers then have a clear insight into what they must develop. From personal experience, while a use case is most beneficial, they are rarely perfect, but they almost always serve a purpose.