[HeyLaughingBoy]

They are, but having users find them is even more so.

We use design reviews, code reviews, unit tests, integration tests and final validation tests. Our bug rate is well below 1/kloc, but bugs still get out the door.

In the end it depends on how you calculate Cost of Quality. In some environments, having a customer experience a bug can have disastrous consequences, in others it's not a big deal at all. We're in the former category :-(