You are what you measure
Posted February 24, 2005 in miscFrom You Are What You Measure : “Many metrics seem right and are easy to measure, but have subtle, counter-productive consequences”. They then go on to give some guidelines for metric selection.
I also like some of the things John Seddon has written. Things like "people use their ingenuity to be seen to be on target in a variety of ways. It is a tragedy that their ingenuity is not engaged in improving the work. ":http://www.lean-service.com/6-19.asp
Another good reference is Basili’s GQM (Goal Quality Metric).