Handled volume and average handle time tell us what happened. But true demand — including the calls we never answered and how long people waited — is what we should be forecasting against for next year.
1
What happened — the metrics we report
Handled volume
820K
calls answered this year
Avg handle time
6.5
minutes per call
Total talk time
88,833
staffed hours of work delivered
2
What it cost — and what we missed
Cost of handled work
$5.59M
handled minutes × cost/min
Avg speed of answer
1:35
average wait before answer
Abandoned calls
101K
demand that left before answer
3
Total demand = handled + abandoned
A full year of demand on the queueTotal demand: 921,348 contacts
Handled820K
Excess55K
Acceptable46K
Handled — counted in our reportsExcess abandoned — above your thresholdAcceptable abandoned — within threshold
4
What it takes to staff — Erlang C
AHT and volume tell you the work. They don't tell you the headcount. Because calls arrive randomly, hitting a target answer time needs more agents than raw workload implies — and that gap grows fast as you ask for faster answers.
Workload (Erlangs)
27.4
agent-hours of work per busy hour
Agents — handled only
29
concurrent, in-seat, on answered calls
Agents — true demand
32
concurrent, in-seat, on all who called
From phones to payroll · true-demand scenario
An Erlang C agent is a body available on the phone during the busy interval — not a hire. Breaks, lunch, training, coaching, leave and admin (shrinkage) mean you must schedule more people than that:
Concurrent agents (Erlang C)
32
In-seat during the busy interval to hit target
Scheduled agents (after shrinkage)
46
÷ (1 − shrinkage) — bodies rostered to keep that many in seat
FTE headcount (annual)
88
Scheduled-agent-hours over the year ÷ paid hours per FTE
Annual cost of scheduled staffTarget: answer within 30s · scheduled hours incl. shrinkage
Budget to handled volume
$12.38M
Staffs only answered calls. Projected ASA: 24s.
Budget to threshold demand
$12.95M
+$570K / yr — staffs for demand above your acceptable abandonment threshold. Projected ASA: 26s.
Budget to true demand
$13.44M
+$1.06M / yr — staffs for all demand including acceptable abandonment. Projected ASA: 27s.
What's inside the cost · true-demand scenario
A blended cost-per-call hides three layers that behave differently. Pulling them apart shows why headcount growth costs more than wages alone:
Steps with headcount — supervisors by span of control, plus a support charge per agent FTE.
Infrastructure + licensing
$0.73M5%
Per-seat licences (scale with agents) + fixed platform & facilities (dilutes as volume grows).
Why this matters for next year
If we plan only to the 820K we handled, we under-build for the 921K who actually called.
Abandonment and ASA are early-warning signals. Rising wait times and abandoned contacts mean real demand exists that handled-volume metrics will never show — until it reappears as repeat calls, complaints, or a service-level miss.
Forecast on handled only
820,000
Plans to last year's answered calls — assumes everyone who called, got through.
Forecast on true demand
921,000
101,000 more contacts to staff for — the gap is what ASA & abandonment reveal.
$129K
Fully-loaded cost per abandonment-driven FTE
Each FTE the hidden demand forces you to hire pulls supervision and a licence seat with it.
Wage $120K · supervision + support $8K · licence + infra $1K