SLAs have a time stamp in them for when they start. The SLA definition specifies a duration for how much time is allotted to meet the SLA. When you start the SLA, the duration is added to the start time to get the planned end time. If you do not have any schedule specified, you are on a 24x7 schedule and the date math is simple, because you just add the duration to the start time.
However, if you specify a schedule with less than a 24-hour day, you are specifying working or business hours, and the SLA only counts during that time. So the business time value calculations are more complicated, because you now calculate the planned end time based on the start time, the duration, the schedule, and the time zone. The schedule associated to an SLA definition requires four business values because, for example, 8 a.m. to 5 p.m. in London is different than 8 a.m. to 5 p.m. in New York, so you need to know the time zone to apply in order to get the proper window for the business hours.
SLA Schedule Business Values
The schedule associated to an SLA definition (contract_sla) is used for calculating the following business values:
- Business elapsed time
- Business elapsed percentage
- Business time left
- Business pause duration
About Business Pause Duration
SLAs frequently have a pause condition, for example, if a customer has opened an incident but has not provided enough information or the right information so you pause while you are waiting for the customer to get back to you with the relevant information so you can continue working on it. When the Pause condition is met, the SLA is effectively suspended. Because you do not know how long the pause is going to last, technically the planned end time value is indeterminate when the SLA is paused. When the SLA comes off pause, the interval between the start of the pause and the end of the pause is added into the pause duration field.
The Business pause duration is an accumulated value. Each time there is a pause, the Pause time is stamped. However, it only counts as a pause if it happens during working hours — totally, partially, or anything in between. So, if an incident goes into pause time at 8 p.m. and goes out at 4 a.m., the pause is completely outside an 8 a.m. - 5 p.m. workday schedule and it's ignored in the business elapsed time calculation.
When you come off Pause to any other state, the duration and the business duration between the current time and the Pause time is calculated and indicated in the Pause duration and Business pause duration fields.
Effect of Schedule Changes
If the schedule is changed during the life of the SLA, the amount of Business pause duration can change, which will affect any ongoing calculations.
For example, say you decide that everyone can now leave work at 3 p.m. instead of 6 p.m., reducing the length of your business day. More Business pause duration time might accumulate than the total amount of Business time for the SLA. Because the total Business time is calculated based on the difference between the start and end time of the SLA calculated against the current schedule settings, the Business elapsed time calculation will be negative, which will be changed to zero.
For these reasons, avoid changing an existing schedule for a running SLA definition. Best practice is to create a new schedule and update the SLA definition to use the new schedule. Any SLA records that are running will continue to use their original schedule, while new SLAs will get the new schedule.
For More Information
- This article is based on Changes to a schedule can cause an unexpected result on an in-flight SLA with business pause duratio... (requires HI login) by edwajs
- Also helpful were some tips from the Community series on "Understanding My SLAs" by iris.geist, especially Part II — The Difference Between Actual and Business Elapsed Times
- Understanding SLA Schedules and Durations, which includes a video!
- The product documentation Actual and business elapsed times topic
- Having an issue with SLAs? Visit the Service Level Agreements (SLA) FAQs
Thank you edwajs for the detailed info.
