Understanding SLA Schedules and Durations

This article helps to understand SLA time duration measurements and provides guidelines for SLA schedules definitions.

Ignore Legacy Fields

The following fields are present on the Task table (but do not appear on the default Task form), which were used by the old Legacy escalation engine: 

• Escalation
• Made SLA
• SLA due

These are legacy fields, and have not been used since the 2010 / 2011 engine were introduced.

Please ignore these legacy fields, they have no relevance to current SLA functionality.

Remove the "Days" element from Duration fields

As described here, the business duration fields (Business elapsed time, Business elapsed percentage and Business time left) for a task SLA are based on a schedule if such a schedule is specified in the relevant SLA Definition. Similarly, the Planned end time of the Task SLA is calculated based on the Schedule and Duration values entered on the SLA Definition.

This can cause some confusion over the different definitions of a "day" between business (form the Schedule) and actual elapsed times.  For example, if you select a Schedule of 09:00-17:00 Monday-Friday on the SLA Definition and wanted a Planned end time in 3 days time you would need to enter 1 day in the Duration field - 8 hour working days multiplied by 3 = 24 hours

One way of reducing this confusion is to modify the Duration field on the SLA Definition, to remove the Days element.

To do this: 

1. Open an SLA Definition record, which shows Days within the Duration field. For example:
   
   
   
   
2. Right-click on the Duration field and select Configure Dictionary.
3. Ensure you are on the Advanced view in the Dictionary record.
4. In the Attributes field, enter max_unit=hours
   
   
   
   
5. Save the record.
6. This removes the Days element from the Duration field in an SLA record. For example:
   
   

Force Population of Business Elapsed Time

By default, if the SLA definition does not use a schedule, business duration fields are left blank.

If you want this to be always populated, you can force this by using a 24 X 7 schedule. 

1. Navigate to System Scheduler > Schedules > Schedules.
2. Create a new schedule.
3. Add a schedule entry to the schedule, checking the All day check box, and selecting Daily in the Repeats field.
   
   
   
   
   Note: if a schedule has no entries, schedule calculation will still work but is highly inefficient.
   
   
4. Submit the schedule entry and save the schedule record.
5. Return to the SLA Definition record, and set the schedule field to be the new 24 X 7 schedule

All future task SLA records will then have business duration fields populated.

• Troubleshooting service level agreements (SLAs)
• KB0547270: Understanding SLA times: actual elapsed time and business elapsed time