Rather than taking a view across 24 hours, we could calculate the work done by an advisor working a 37.5 hour week.
In this case, the calculation would be:
Agents(80%, 30, 20,000 / 37.5, 330) x 37.5
That is, the number of advisors required per hour in a rota multiplied by the number of hours in a rota.
This calculation gives 2,063 call-taking hours required, almost half-way between our first calculation and what the accountant expected.
The problem with this is that it effectively “squashes” volume up in the calculation, leading to a lower expectation of required availability. Such under-cutting will lead to insufficient staffing to deliver the service level unless the opening hours of the centre are actually 37.5 hours per week.