For SLA Config you can select a type of SLA Timer calculation: a Multi-Cycle or First Cycle options.
When you choose Multi-Cycle, the SLA timer runs every time the Start condition is met. So as the result you will get SLA time as the cumulative sum of all cycles' duration between origin and end statuses.
This feature is available only for SLA config with SLA Goal based on a time limit (hours:minutes) and is disabled for a negotiated date goal. Read more here.
Otherwise, SLA time will be calculated for the first cycle only.
Here is how SLA time will be calculated when you choose either a Multi-Cycle or First Cycle options.