The Annals of Applied Statistics

Workload forecasting for a call center: Methodology and a case study

Sivan Aldor-Noiman, Paul D. Feigin, and Avishai Mandelbaum

Full-text: Open access

Abstract

Today’s call center managers face multiple operational decision-making tasks. One of the most common is determining the weekly staffing levels to ensure customer satisfaction and meeting their needs while minimizing service costs. An initial step for producing the weekly schedule is forecasting the future system loads which involves predicting both arrival counts and average service times.

We introduce an arrival count model which is based on a mixed Poisson process approach. The model is applied to data from an Israeli Telecom company call center. In our model, we also consider the effect of events such as billing on the arrival process and we demonstrate how to incorporate them as exogenous variables in the model.

After obtaining the forecasted system load, in large call centers, a manager can choose to apply the QED (Quality-Efficiency Driven) regime’s “square-root staffing” rule in order to balance the offered-load per server with the quality of service. Implementing this staffing rule requires that the forecasted values of the arrival counts and average service times maintain certain levels of precision. We develop different goodness of fit criteria that help determine our model’s practical performance under the QED regime. These show that during most hours of the day the model can reach desired precision levels.

Article information

Source
Ann. Appl. Stat., Volume 3, Number 4 (2009), 1403-1447.

Dates
First available in Project Euclid: 1 March 2010

Permanent link to this document
https://projecteuclid.org/euclid.aoas/1267453946

Digital Object Identifier
doi:10.1214/09-AOAS255

Mathematical Reviews number (MathSciNet)
MR2752140

Zentralblatt MATH identifier
1185.62204

Keywords
Call centers QED regime square-root staffing forecasting arrival count exogenous variables

Citation

Aldor-Noiman, Sivan; Feigin, Paul D.; Mandelbaum, Avishai. Workload forecasting for a call center: Methodology and a case study. Ann. Appl. Stat. 3 (2009), no. 4, 1403--1447. doi:10.1214/09-AOAS255. https://projecteuclid.org/euclid.aoas/1267453946


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