[valenterry]

The funny thing is, except for "tickets closed" and maybe "costs saved" there is no metric here you can directly attribute to a single developer, and probably not even a team.

Even "hours worked". What do you mean, hours spent in the office? How do you know the person was not drinking coffee or staring at their code in thought of something else.

That being said, I think your metrics are good. And even single developers should be measured by them (which means all developers get measured by the same metric and get the same value). Why? Because it helps the business of SLAs are hit, no matter why they are hit.