Well written user scenarios put all the 'features' into a flow that is relevant to the user's value stream. They can help us design a solution as a unified value stream rather than just a bunch of features put together. From Lean Solutions:
"Companies must provide the goods and services consumers actually want, when and where they are wanted, without burdening the consumer."For more information and an example, check out Jeff Patton's stickyminds article.