Other Obvious Best Practices

We'd think this patently obvious if we hadn't worked on or known about software development projects that didn't do this: you need adequate source-code control. With ineffective source-code control, or none, you're testing a moving target at all times. You need the ability to build with a known snapshot of code and return to a previous snapshot whenever necessary.

When the team has performed a successful integration, label it and promote it to the acceptance-test environment. Collective code ownership can't work without source-code control anyway, so we'd think all Extreme Programming teams would have it. Still, sometimes one has to state the obvious.

Acceptance test cases, automated test scripts, and test results must also be kept in the source-code control system. The whole team will have collective ownership of these as well as the production software. It's vital that programmers be able to see the most current acceptance tests at all times. It's also essential that anyone who wants to kick off acceptance tests can get the correct version of automated tests to run.