How does SLA or Milestones works when Service Request Reopened, and add team member within SR

Summary:

Hello,

We would like to know if someone have any insight on below points.

1. How does SLA or Milestone works when help desk user Reopened the Service Request? if this will continue the time for SLA or it will go back to 0
2. If Help Desk Agent add team member within service request to share the workload to balance, how SLA works in this case?

Thanks

Vidya

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