Work out contact centre staffing instantly with clear inputs, formula shown and shareable results.
Staffing has two steps. Erlang C gives the agents needed on calls to hit the service level, then shrinkage converts that into rostered headcount: breaks, training, meetings, holiday and absence typically consume 30 to 35 percent of paid time. Skipping the shrinkage step is the most common reason contact centres are understaffed against their own model.
Staffing with shrinkage
traffic = calls x AHT / 3600; agents = smallest N meeting the Erlang C service level; rostered = ceil(agents / (1 - shrinkage))
Everything that stops a rostered agent taking calls: breaks, lunch, training, coaching, system downtime, holiday and unplanned absence.
Erlang C is highly non-linear near the traffic level. Going from 24 to 25 agents can move service level by ten points or more when the queue is close to unstable.