In earlier hours we learned that lack of ongoing customer involvement was a common thread between the project failures and runaways. The RAD methodologies we covered during our first hour were an attempt to bring the customer back into development. With RAD, developers prototyped the application with customers or users, it was then signed off and development began. This method has serious drawbacks, not the least of which is the lack of flexibility; the customer is still locked in while development carries on at full speed.
With XP, we get extreme about customer involvement. we'll mandate that the customer be on the project full-time for the duration and be located on-site with the team. On-site then means on-site! Remember that we're developing with one team, a team that includes customers. Look at it this way: How could your team develop any other way? If developers are coding from user stories that lack detail and call for clarity, they will have to speak to the customer.
Another feature of XP is the high level of communication and feedback that the team thrives on. Talking, listening, questioning, and so on. How could you do this when not sitting side-by-side with your customer?
The customer could include, users, business experts, and any other customer-side resource.
The customer will be taking part in the Planning Game, working through business requirements, prioritizing, and defining. When development starts the customer will be entering into ongoing conversations as developers begin coding.