Probability of Staff absence - Poisson formula

This file is useful to calculate the probability of an event, based on the Poisson formula.

It's used to prepare forecasts or foresee trends.

In this case it's made to calculate the probability of having absent staff in your own team, but it can be used for any other historical data.

In my experience, with 20 collaborators, I can say it's very useful as history doesn't repeat itself but it often rhymes.