Ha-ha, the joke is on you, the systems I have inherited do not have tests. Joke aside, tests are a great resource when they are present. The other technique I

Ha-ha, the joke is on you, the systems I have inherited do not have tests. Joke aside, tests are a great resource when they are present. The other technique I have used was to look at the system like a black box, and only look at the expected behavior at the boundary. Sometimes, it is the fastest way to clear old cruft.