Chapter 14. Acceptance Tests and Quality

We thought we had the Great Plains figured out in yesterday afternoon's drive through western Iowa, but today we find out that was just the beginning. The rolling tallgrass prairies of Nebraska beckon us westward under an endless sky, and we begin to notice other things besides grass. As we look more closely, flowers, trees, birds, mammals, and insects (yuck! turn on the windshield wipers) become apparent.

The acceptance tests we defined on the first day of our test drive were at a high level. They were just enough to document an assumption and hang a ballpark estimate on for release planning. During iteration planning, we took a closer look at our tests and all the tasks required to accomplish them, giving us a better understanding and more detailed estimates in iteration planning. Now that we're done estimating for this iteration, we're ready to get down to doing the work.

This iterative approach is important to being able to move with sufficient speed through an XP iteration. At each step, you must defer as much detail as possible to the next, dealing only with items you absolutely can't put off. Without a risk of being left by the roadside in a cloud of dust, you can't expect to nail down every detail to the last gnat's eyelash before moving on. Our lunch stop today is at a place called the Brick Wall. Let's not run into any of those on our test drive.