Not sure what you mean by "80% breached" - do you mean it's breached and it's now 80% over time, or there's another 20% to go until it's breached?
Either way, the steps are:
- Make a copy of the "Default SLA Workflow" template, calling it something else.
- Change the notification threshold from 50% - or add another threshold time in for 80%
- For this SLA, specify the conditions under which it will apply to an incident (possibly disabling the other SLAs)
Note that the notifications aren't done directly, but by raising events (sla.warning and sla.warning.breach) so you may want to create different events (such as sla.warning.80) and have notifications firing off against that event occurring. Notification recipients can then be specified as a group, rather than an individual.
I'd recommend you have a word with your platform administrator - we cover basic workflow editing and SLA conditions on our Sysadmin course, so they should be able to help you.
