You are what you measure

Summary
Be careful with metrics. You might get what you ask for

From 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.

Another good reference is Basili’s GQM (Goal Quality Metric).