Can somebody help me to establish the SLA metrics for QA's activities.
What metrics we should use? How to collect the data?
You should use the measurements that are:
a) applicable to what you are attempting to show/measure
b) that you can capture objective data that can be measured.
It is very unusual for SLA to be used as a measurement in project work which is generally where QA activities take place.
I have not failed. I've just found 10,000 ways that won't work" --Thomas Edison