Does the Erlang C model fit in real call centers?

Thomas R. Robbins, D. J. Medeiros, Terry P. Harrison

Research output: Chapter in Book/Report/Conference proceedingConference contribution

17 Scopus citations


We consider the Erlang C model, a queuing model commonly used to analyze call center performance. Erlang C is a simple model that ignores caller abandonment and is the model most commonly used by practitioners and researchers. We compare the theoretical performance predictions of the Erlang C model to a call center simulation model where many of the Erlang C assumptions are relaxed. Our findings indicate that the Erlang C model is subject to significant error in predicting system performance, but that these errors are heavily biased and most likely to be pessimistic, i.e. the system tends to perform better than predicted. It may be the case that the model's tendency to provide pessimistic (i.e. conservative) estimates helps explain its continued popularity. Prediction error is strongly correlated with the abandonment rate so the model works best in call centers with large numbers of agents and relatively low utilization rates.

Original languageEnglish (US)
Title of host publicationProceedings of the 2010 Winter Simulation Conference, WSC'10
Number of pages12
StatePublished - 2010
Event2010 43rd Winter Simulation Conference, WSC'10 - Baltimore, MD, United States
Duration: Dec 5 2010Dec 8 2010

Publication series

NameProceedings - Winter Simulation Conference
ISSN (Print)0891-7736


Other2010 43rd Winter Simulation Conference, WSC'10
Country/TerritoryUnited States
CityBaltimore, MD

All Science Journal Classification (ASJC) codes

  • Software
  • Modeling and Simulation
  • Computer Science Applications


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