From what I've heard and read, it tends to have more to do with the manager either not working closely with the individuals and/or not understanding what they a

From what I've heard and read, it tends to have more to do with the manager either not working closely with the individuals and/or not understanding what they are doing. This is especially common when it's a non-developer managing the group. The best measure of productivity is the amount of functionality added and the number of bugs produced. Secondary metrics would be the same two numbers for when someone else makes the changes. Of course, the real trick is in accurately gauging the difficulty of the tasks.