How to predict the required number of employees (for a call center)?

Question

Forecasting

Hello.
There is a task in which it is necessary to predict the required number of employees on a shift (every day, by the hour), relatively speaking for 1 month (this is not indicated in the task, maybe for two weeks).

There is one channel of appeal - calls to the hotline.
The average number of calls per day is 567, calls are received unevenly, in the period from 16:00 to 02:00 22% more than at other hours.
SL (service level) on the 80/20 channel.
The average processing time for one call is 182 sec. Work schedule - 4/2, 9-hour work shift. The shifts themselves are divided as follows: Usually they leave from 8 am to 5 pm, from 1 pm to 10 pm, from 5 pm to 02 am.

How to find out how many employees per day will be optimal?

ps I'll add. You need to calculate for a day (not for a month or two weeks). I don't have the original number of staff. I have to decide, given the above inputs, what would be the optimal number of employees.

Answer 1

Modeling and calculations for Erlangs.
Here is a good calculator for a daily download.