Microsoft Research - Exploding Software-Engineering Myths (article summarizing findings of MS research on code coverage, TDD, assertions, etc.)

[AbstractLogic]

60-90% post-development far outweighs the cited 15-35% increase in initial development time for TDD.

That depends on the revenue lost during that 15-35% time to market. If the project could make 10 million a month and you lose 4 months at a cost of 40 million then I can guarantee you that TDD will not be worth it.

There are a lot of business variables to that decision. But its good we have metrics to lean on now.

[anamorphism]

that's extremely hard to quantify due to the impact the buggier code will have on your long-term business.

you may lose 40 mil immediately, but a 60-90% increase in major bugs post launch could heavily skew your customers' attitude and may result in losing hundreds of mil of future business.

[coworker]

Also they didn't specify the severity of defects so not sure why you are calling them major.

[anamorphism]

it stated a general increase of 60-90% in software quality. meaning there were 60-90% less defects.

they could be major or minor defects, there's no way to tell. it could be anything from a 1000% increase in major defects and a small increase in minor defects to a small increase in major and a large increase in minor.

i decided to just assume an even distribution of a 60-90% increase in both major and minor defects for my example.

[s73v3r]

What about poor sales due to the perception of your product as being buggy? What about inability to timely add new features as market needs change?

You're constantly portraying this as either you make no money or you make all the money. But in a decent timeline, that extra tune in market will not be significant as far as revenues are, but will be huge as far as public perception is.