Shiftmate

Erlang-C call center personnel calculator

Calculate the number of agents required with call volume, AHT, service level, response time and shrinkage.

Prepared by:Shiftmate Product and Operations Team · Son kontrol:

Step by step usage

  1. Enter actual period data

    Replace the sample values with your own business's data for the same date range and the same unit of measure.

  2. Read the result and assumptions together

    It calculates traffic load from vehicle call volume and AHT, iteratively finds the lowest number of active agents that meet the target service level, and adjusts the total planned staffing upwards for shrinkage. Examine the result not just as a single number but for its sensitivity to change in inputs.

  3. Save the scenario and measure again

    Once you make a decision, write down the input and the date. Take volume and AHT from the same interval. Separate active need and planned staffing. Test the result with the real abandon and arrival distribution.

What does this tool calculate?

Calculate the number of agents required with call volume, AHT, service level, response time and shrinkage.

formula

Traffic load (Erlang) = number of calls × AHT / interval seconds; staffing is available with Erlang-C service level solution and shrinkage correction

Calculation method

It calculates traffic load from vehicle call volume and AHT, iteratively finds the lowest number of active agents that meet the target service level, and adjusts the total planned staffing upwards for shrinkage.

Worked example

180 calls per hour. AHT 300 seconds. Target is 80% / 20 seconds. Shrinkage 25%. Result: The tool shows the number of agents that are active and need to be scheduled, the estimated service level, along with ASA and occupancy.

How should the result be interpreted?

Take volume and AHT from the same interval. Separate active need and planned staffing. Test the result with real abandon and arrival distribution

Common usage mistakes

Entering the daily call into an hourly interval. Applying the shrinkage ratio in the wrong direction instead of adding it to the active roster. Ignoring Erlang-C's abandon assumption

Limits of the model

Erlang-C assumes that calls do not leave the queue and that arrival/service distributions comply with model assumptions. With small or highly variable intervals, the actual result may deviate.

Is your data safe?

Calculation and file analysis runs in your browser. The operation files you upload are not sent to a server by this tool.

Relevant official and technical resources

Frequently asked questions

Is Erlang-C used for outbound or chat?

The basic model is for inbound single-contact queue waiting; A different model is required for outbound, abandon or simultaneous chat.

Why is shrinkage added later?

Erlang-C gives the active queue capacity; Planned staffing for breaks, meetings, training and absences is also enlarged.