Callback smoothing

A callback doesn’t remove work — it moves it off the peak. This tool sizes your busiest interval with Erlang, then shows how many agents you save at the peak when a share of those contacts take a callback and are handled in a quieter interval instead. It also shows the deferred work (with its retry cost) you need to find room for later.

Your peak interval

How it works

The peak interval is sized with Erlang C at your service target. Moving a share of peak contacts to a callback reduces the peak load, so the calculator re-runs Erlang on the smaller volume — the difference is the peak headcount you save. Those deferred contacts don’t vanish: they have to be handled later, and because callbacks generate failed attempts (no answer, voicemail), the retry uplift adds to the work you must find trough capacity for. Treat the callback queue as a backlog with its own service promise — called back within a set window — not a queue you can ignore. Read the callbacks and virtual queuing article for the planning logic.