Always test, test, test ...

Thiokol and Marshall evaluated the SRM and its case joints in structural, pressure, and static firing tests beginning in 1976. Because tests of the large solid rocket were more expensive than liquid engines, engineers ran fewer tests.

 Taken from The Challenger Accident http://history.msfc.nasa.gov/book/chptnine.pdf

The Joel Test

The Joel Test

1. Do you use source control?
2. Can you make a build in one step?
3. Do you make daily builds?
4. Do you have a bug database?
5. Do you fix bugs before writing new code?
6. Do you have an up-to-date schedule?
7. Do you have a spec?
8. Do programmers have quiet working conditions?
9. Do you use the best tools money can buy?
10. Do you have testers?
11. Do new candidates write code during their interview?
12. Do you do hallway usability testing?

http://www.joelonsoftware.com/articles/fog0000000043.html