For example, if we were trying to deliver against a user story of, ‘Able to purchase with a credit card’, we might want to ask which credit cards must be included in order for our release to be ‘accepted’ by the customer.

In other words, we are agreeing a level of value that must be achieved for the customer’s need to be met. Achieving ‘done’ means that something is ready to be released or shipped (should we want to) because it is functional and fulfils the original need in the eyes of the customer.