if we changed the assignee who will responsible for ticket breach the first assignee or the last

[imtiaz.ali]

if we changed the assignee who will responsible for ticket breach the first assignee or the last

[Rudy Holtkamp]

Hi @imtiaz.ali, you should ask yourself if it really matters.

As a support team, you are responsible for handling tickets, who takes what amount of time is for a customer perspective not important. The fact that he/she is not helped within the SLA time is. So the team is responsible. Even if you were not an assignee, you are still responsible. Otherwise, you will see that service desk agents will only work on the tickets they can easily fix. 

So I would not recommend to play the blame game within your support team.

[imtiaz.ali]

i want to know the technically how jira treat 

[Rudy Holtkamp]

There is no field that shows the person that broke the SLA. Of course, you can record it if you want to, but from an agent point of view, what is stopping me from quickly assign it to somebody else if the SLA is about to break and a minute later, put it back on my name again? 

From a JSD point of view, it only matters that the SLA has been broken not who did it.

[imtiaz.ali]

can we take rights from agents to assign the ticket to some one else 

[Rudy Holtkamp]

Only agents are able to handle tickets. Other Jira users (Core or Software) are able to comment and create attachments only. They are not allowed to change values in custom fields or transition the ticket to another status.