Sum of the SLA Cycle of an Issue including the Report

Currently, JIRA Service Desk SLA will still retain how long has it been runnin even it is moved to another SLA. When it is stopped and start the SLA again, there will be a box beside the SLA letting the Agent now how long has it been elapsed until it the SLA stop which is good.

But, it will be great if we could SUM the total of how long the SLA have been elapsed whether when for Cycles that the SLA Met or Not. Then, generating a Report for it as well about the Issue SLA Changes.