I have heard many managers in software companies trying to measure productivity based on Velocity of the team. I think it makes no sense.
Here are some of my thoughts:
1. Velocity is measure of team's capacity to deliver certain functionality within a specified interval. This definition makes it clear that, one cannot use the velocity as the stick during appraisal and performance evaluation for individual members.
2. You cannot use velocity to measure the productivity between teams also. Reason being, each team is different. Two teams with 10 developers each, cannot be compared. Each team would come from varied years of experiences, domain knowledge, maturity, support from product owners, communication skills, etc.