Abstract. The operation of call centers can be modeled by queues with impatient customers in order to dimension the appropriate number of agents given the call volume and the caller's satisfaction level for service. An exposition of theoretical results for the M/M/m/(m+c) queueing model with impatient customers is presented with numerical illustration as a basic model of call centers. The patience time of each customer in the waiting room is assumed to be exponentially distributed. In particular, we derive the joint distribution for the waiting time of a customer and the probability that he is served and the probability that he abandons while waiting. The results can be used to calculate service level indicators for the operation of call centers.

Received: December 18, 2013

AMS Subject Classification: 60K25, 68M20, 90B22

Key Words and Phrases: queue, waiting time, impatient customers, abandonment, call center

Download paper from here.