"According to the study, putting a specification in place before development begins can result in a 50 percent increase in success, and making sure the requirements are accurate to the real-world problem can lead to a 57 percent increase"

Thank You Captain Obvious

So when the project spec is unclear? And/or changed during project? Abandon ship??

Or, utilize a methodology that's capable in adapting to mid-project changes....?

Hmm.... I wonder....