DDP Discussions and challenges

Several people have asked about benchmarks for DDP. I have actually blogged about this, but my comments are "buried" in the comments to the post about "Starting with DDP". Please have a look at the comments for that post, which include:

- benchmarking DDP with other organisations (raised by Bernhard Burger)

- Paul Herzlich's challenges about the seriousness of defects, getting data, DDP being hard to use and code-based metrics (all of which I have replied to in my following comment)

- using DDP to improve development (raised by Ann-Charlotte)

- Michael Bolton's challenges:

5 examples to show when it doesn't work (which I reply to in my first comment following his) (including some Dilbert Elbonian testers ;-)

7 "problems" - some of which I agree with, some I don't understand, and some I think illustrate the benefit of DDP rather than being problems with it (replied to in my second comment after his)

Thanks to Michael B's comments, I also formulated 3 Rules for when to use DDP:

DDP is appropriate to use when:
1) you keep track of defects found during testing
2) you keep track of defects found afterwards
3) there are a reasonable number of defects – for both 1) and 2)

These are not the whole story (as illustrated by Michael's examples) but I think are a pre-requisite to sensible use of DDP.