Hello,
There are out of box Service Level Agreements (SLAs) for the incident table and separated by priority: https://docs.servicenow.com/bundle/rome-it-service-management/page/product/service-level-management/...
The priorities are an outcome from the priority lookup rules: https://docs.servicenow.com/bundle/rome-it-service-management/page/product/incident-management/task/... - which takes the urgency and impact field values and based on the combination of those two values, the priority is determined.
However, out of box, there's no "definitive" timing for resolution as that should be determined by your business. ServiceNow has default suggestions (as I mention above regarding SLAs), but you all would want to review these and adjust, if applicable.
Please mark reply as Helpful/Correct, if applicable. Thanks!
