Workforce management, or WFM, is the discipline of forecasting contact volume, then scheduling the right number of agents with the right skills at the right times to meet service level targets without overstaffing.

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‍Why it matters

Understaffing during a spike causes long queues, high abandonment, and stressed agents, while overstaffing wastes labor cost that adds up fast at scale. WFM sits between those two failure modes, and its mathematical core is usually the Erlang C formula, developed by Danish mathematician Agner Krarup Erlang in 1917, originally to calculate how many telephone operators a switchboard needed. The same underlying math, translating expected volume and handle time into a staffing number, still runs most modern scheduling software.

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‍How it runs in practice

WFM works in stages, forecast expected volume per interval, often broken into 15 or 30-minute blocks, calculate required staffing per interval using Erlang C, add shrinkage on top to get the real hiring number, then build schedules and adjust in real time as actual volume comes in against forecast. A classic baseline service level target is answering 80% of contacts within 20 seconds, though the right target varies by channel and business.

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‍Where it gets harder

Omnichannel support complicates the math, since Erlang C was built around phone queues, and chat, email, and social media don't behave the same way, an agent can often handle more than one chat at once, which single-channel voice staffing math doesn't account for. Teams running omnichannel operations typically layer additional models or simulation on top of a base Erlang C calculation rather than relying on it alone.