[kqr]

This looks like a much more sophisticated version of PERT than I have seen used. When people around me have claimed to use PERT, they have just added together all the small numbers, all the middle numbers, and all the big numbers. That results in a distribution that is too extreme in both lower and upper bound.

[baq]

that... is not PERT. it's 'I read a tweet about three point estimates' and I'm using a generous interpretation of read