Erlang C is a traffic modeling formula used in call center scheduling to calculate delays or predict waiting times for callers. Erlang C bases its formula on three factors: the number of reps providing service the number of callers waiting and the average amount of time it takes to serve each caller. Erlang C can also calculate the resources that will be needed to keep wait times within the call center s target limits. This method assumes that there are no lost calls or busy signals, and therefore may overestimate the staff that is required. -Erlang C is a traffic modeling formula used in call center scheduling to calculate delays or predict waiting times for callers. Erlang C bases its formula on three factors: the number of reps providing service　the number of callers waiting　and the average amount of time it takes to serve each caller. Erlang C can also calculate the resources that will be needed to keep wait times within the call center s target limits. This method assumes that there are no lost calls or busy signals, and therefore may overestimate the staff that is required.