I just published a Basic Guide to Days of Risk over on my CSO Magazine Blog, in preparation for a new quarterly days-of-risk study I'm going to start publishing.  If you don't have a good understanding of the days-of-risk metrics, the post will give you the background on the metric and reference several documents that have published results using the metric.

I also meant to provide the guide in a downloadable format, but didn't get that done, so I'll attach the guide as a download in a couple of days.

Regards ~ Jeff