Most software professionals believe that testing software is essential to quality. Where people inside the industry differ is how to accomplish that testing, as strategies vary by level of the application tested, tools, methodology, amount of automation, and who completes the testing itself. The aspirational desire is to ship high-quality bug-free software no matter how one gets there. However, the devil is in the details. The promise of quality software Central to creating a testing strategy that works are four essential questions: