I came across this quote from Shigeo Shingo; "Inspection to prevents defects is absolutely required of any process but that inspection to find defects is a waste."
I brought up the quote in a webinar I was giving on Six Sigma last week and it brought some interest from the audience. So how do you test you product?
I've been in many QA roles through my career. Writing test cases, reviewing test results, re-engineering a testing process. The best approach that I've found is to get the end users involved in testing early in the process. The folks that are using the software (or whatever you're building) should write the test cases on how they would like to see it tested, as the requirements are being captured, not after the product is developed. Scott Ambler refers to this as Test Driven Development.
On a related note, Dave Prior has a post talking about being done and being done done. So when is testing done? Is it after development is done, i.e., waterfall? Or is testing integrated into your development process?
Quality should be built into the product, not inspected for after completion.