[andersonvieira]

I recommend reading http://www.amazon.com/Measuring-Managing-Performance-Organiz... for an analysis of how motivation systems based on measurements often become dysfunctional.

Dysfunction may arise when you are unable to measure all the relevant dimensions of the work being performed. People will often shift their effort to the dimensions that are being measured and ignore the remaining tasks, no matter how important they are. This results in less value being delivered compared to a scenario with no measurement based incentives.

The author mentions software development as an area that is specially prone to dysfunction.