OK, the first and most important quality graph is unit test scores over time. Here it is (see Figure 18.2). Copy it out of the book and post it on the wall.
That's right. You must have unit tests for everything that could possibly break, and they must always be at 100 percent, for every release of code by every programmer. That's one graph done.
The official public XP measure of quality is, of course, your acceptance tests. What are the most important dimensions of acceptance tests?
The number of acceptance tests gives a good measure of the scope of your testing. And the ...