Average speed of answer

Abandonment rate is the share of customers who leave a queue, chat, or callback line before ever reaching an agent. Contact centres track it alongside wait time because abandonment climbs sharply once queues pass a customer’s patience threshold, making it an early signal that staffing or deflection is not keeping pace with demand.

A queue is the ordered set of contacts waiting to be handled, usually segmented by channel, language, skill, or customer tier. Queue design determines who waits and for how long, making it one of the most consequential and least visible decisions in a support operation.

Time to first response is how long a customer waits before any human or AI reply arrives. It is the most visible service measure to the customer and the easiest to improve with automation, which is why it should always be read alongside resolution quality.

Service level is the percentage of contacts answered within a set time threshold, written as two numbers such as 80/20: 80% of calls answered within 20 seconds. The threshold is a business decision rather than a fixed standard, and while 80/20 is the most commonly cited target, its origin is debated and it lacks rigorous research backing. Staffing to hit a target service level typically relies on the Erlang C queuing formula, and service level moves together with abandonment rate, since more callers hang up as wait times grow. Example: if 850 of 1,000 calls are answered within 20 seconds, service level is 85%.