Response rate rate for support staff - how to?

[Deleted user]

Hi

I am looking into having a SLA of measuring a response rate of the specific group of people in a Service Desk Project to tickets created by everyone to this project. Due to the nature of the tickets the resolution rate is not a good SLA to track as we are not the ones solving the issues, and i would like to increase the the update/response rate given to tickets with a trackable SLA. What would be the best way to create a filter that we can sort the tickets in where we can track the responserate and have it as a sort criteria as well? 

i.e. one thing is we would like to have a criteria where we can sort by last response made by support staff (specific people not by everyone) and then to be able to track a KPI on it on a weekly monthly basis with reports. In a way, this is also good to have as a filter so we can see the time since last update made by Us to tickets in a project  

Seems to be a harder task, especially for Jira Cloud

Thank a bunch in advance, hope to find the answer