Quality of Service (QoS) is the number of calls handled in relation to the number of calls received. It is expressed as a percentage. This is one of the key performance indicators of a call centre. The minimum quality of service (QoS) of our centre is 75%. This means that out of 100 calls received a minimum of 75 must be taken. Respecting the limits of call times thus makes it possible to achieve this objective. ©