The ARRIVALRATE function calculates the maximum interval between requests possible while processing a specified percentage of these requests.

For example, you can use the ARRIVALRATE function to calculate how much time agents have available for other tasks.

ARRIVALRATE(Number of servers, SLA, Target response time, Average duration)

ArgumentData typeDescription
Number of serversNumberThe number of servers (for example, call center agents) available to process requests.
SLANumberThe percentage of requests that need to be processed within the Target response time.
Target response timeNumberThe time period within which each request must be responded to.
Average durationNumberThe average duration it takes to process each request.

The ARRIVALRATE function returns a number. This is the maximum possible interval between the arrival of requests while processing the percentage of requests specified in the SLA argument.

The Target response time and Average duration arguments do not have to use a specific time unit. For example, they can use seconds or minutes. However, both arguments must use the same time unit.

The maximum number you can use for the Number of servers argument is five million.

Call center planning functions are unavailable in Polaris. Learn more about the differences between Anaplan calculation engines.

In this example, the Call Centers list is on columns, and line items on rows. The first four line items contain the data for the ARRIVALRATE function for each call center:

  • The number of servers available to process requests
  • The percentage of calls that must be responded to within the target response time, or SLA
  • The target time to respond to calls within
  • The average duration it takes to complete requests

The Arrival rate for SLA line item uses the ARRIVALRATE function to calculate the fastest arrival rate requests can be answered within while the SLA is maintained.

The Increased SLA line item enables you to amend the SLA. This is used in the formula in the Arrival rate for increased SLA line item, which calculates the fastest arrival rate requests can be answered within while the increased SLA is maintained.

Both of the line items that contain formulas use the Percentage format with two decimal places to display the possibility as a percentage.


Call Center 1Call Center 2Call Center 3Call Center 4
Number of Servers17243924
Service Level Agreement85%97%92%85%
Target Response Time15181712
Average Duration18.6723.2524.8717.39

Arrival rate for SLA

ARRIVALRATE(Number of Servers, Service Level Agreement, Target Response Time, Average Duration)

0.82010.94811.4551.266
Increased SLA90%92%97%90%

Arrival rate for increased SLA

ARRIVALRATE(Number of Servers, Increased SLA, Target Response Time, Average Duration)

0.80150.92881.4131.243