Advance Planning Pays Off

On one of our projects, a team of programmers and analysts met at length with customers before the start of the project to define preliminary stories. During the project, these stories were used as a basis for release and iteration planning but were also expanded into functional requirements that the traditional customer felt more comfortable having as artifacts.

You can also use this time, before the first iteration starts, to educate the customer on how development will proceed and set his expectations about XP. Maybe you don't even call it Extreme Programming. Just explain how it will work from his point of view. He'll get to write up all the features he wants as stories. He'll get to choose his highest-priority stories every two weeks and see the finished result at the end of the two weeks. Sometimes the team may not complete all the features he wants for an iteration, but he'll be informed. He'll be allowed to make adjustments throughout the life of the project.

As we mentioned earlier in the book, one company created an XP owner's manual for customers, to help them understand their roles and responsibilities on the project. Customers must know they have to drive decisions about how the software will work from the business point of view and that it's most productive if they let programmers make the technical decisions. To steer safely and speedily down the road, they have to understand how to operate with XP.

We've talked in earlier chapters about managing customers' expectations, but this is an area that can't be emphasized too much. With large projects, it may be impossible to deliver, at the end of any particular iteration, functionality the customer can actually use for his business. In the project Schalliol wrote about, he said, "We had to prepare our customer to be patient with partially finished business functions after certain iterations were completed."