- Over the last several years managers, directors, and executives have asked me to present empirical evidence that Agile will cost them less money and take less time
- A recent paper (here) published by Microsoft and IBM, showed that practicing TDD versus general unit testing reduced bug density by 40-90%. Reading this paper gave me one data point; bugs are one of the three things listed above that customers hate the most. The question is can bugs be equated to time and money?
Overall the author of the blog has the right idea, that TDD is the way to go! However, he seems to conflate agile and Test Driven Development. They are two distinct things. One can practice agile and not TDD and vice versa. Now we can debate whether or not you should write unit tests for "private" methods :)