Abstract
To detect the number of agents needed to serve customers, it is necessary to consider the call centre as a mass service system. Then it is possible to asses the convenient number of agents according to the probability of the system receiving a request and the time in which the request is serviced by employing a Markov chain and the Erlang model. In an archetypal call centre, the incoming calls are added to a waiting queue and subsequently they are assisted by an agent. In case all agents are occupied, the customer has to wait in the queue until one of the agents becomes available. It is, therefore, important to compromise on the number of agents and the time the customers spend waiting in the queue. The result should be that there are enough agents in the call centre to serve the customers in the time required. This article focuses on solving this problem.