Queuing Models - A Call Center Case

We look at the Erlang C model, as a queuing model generally used to examine call center performance. Erlang C is a simple model, which does not take into consideration caller abandonment and is the model most usually used by experts and researchers. We compare the theoretical performance forecasts of the Erlang C model to a call center simulation model in which a lot of the Erlang C assumptions are liberated. Our discoveries demonstrate that the Erlang C model is subject to important error in forecasting system performance, but that these errors are massively biased and most probably to be pessimistic, the system has the tendency to perform better than forecasted. It can be the case that the models tendency to give pessimistic estimates helps clarify its continued popularity. Forecast error is powerfully correlated with the abandonment rate thus the model works best in call centers with large numbers of agents and almost low utilization rates.