SLA calculation
SLAs are calculated and assessed by a business rule and scheduled jobs that run in the background.
One solution is to specify elapsed percentage in SLA notifications by using notifications for each percentage level. For example, an email notification for "75 percent SLA Warning" is created and a special event is used to trigger that notification. The event can be called "sla.warning.75". Another solution is hard-coding these email notifications to trigger at a specified duration percentage, and configure the workflow linked to that SLA definition to send an email notification after waiting an elapsed percentage.