Image via WikipediaHey, something like proof that going without unit-tests will let you ship faster, but at the penalty of technical debt in the code base. (I realize that isn't _exactly_ what was demonstrated ;)
“The nice thing about working at Microsoft,” Nagappan says, “is that the development organization is large enough that we could select teams that allowed for an apples-to-apples comparison. We picked three development projects under the same senior manager and looked at teams that used TDD and those that didn’t. We collected data from teams working on Visual Studio, Windows, and MSN and also got data from a team at IBM, since the project was a joint study.”
The study and its results were published in a paper entitled Realizing quality improvement through test driven development: results and experiences of four industrial teams, by Nagappan and research colleagues E. Michael Maximilien of the IBM Almaden Research Center; Thirumalesh Bhat, principal software-development lead at Microsoft; and Laurie Williams of North Carolina State University. What the research team found was that the TDD teams produced code that was 60 to 90 percent better in terms of defect density than non-TDD teams. They also discovered that TDD teams took longer to complete their projects—15 to 35 percent longer.development cycle of 12 months, 35 percent is another four months, which is huge,” Nagappan says. “However, the tradeoff is that you reduce post-release maintenance costs significantly, since code quality is so much better. Again, these are decisions that managers have to make—where should they take the hit? But now, they actually have quantified data for making those decisions.”"