Hi,

This is a question I already had in my mind when I read the *Hyper* book and it came back to me when reading the latest *Tame Your Work Flow*.

The following Beta probability distribution is used in both books to illustrate the probability of projects duration:

Where is this distribution coming from? Is it a mental model or is it indeed factual?

As a side note, when I collected flow time data from one team few months ago and plotted the values in a histogram I was surprised to see the distribution did indeed match roughly the one above. So I’m really curious to find more about it.

Thanks in advance,

Daniel.