This is version 0.1 Build 11. The change between Build 10 and 11 included a major change. While testing, I learned that I wrongly set the order of the alpha and beta shape parameters between P4:Z15, so the implied shape of the curve was skewed on the opposite side of where it should have been. The formula changes, then, correctly set the alpha and beta shape parameters so when a 3-point estimate implies a left-skewed curve, the shape parameters create an implied, left-skewed curve (and vice versa for a right-skewed curve).
There were a few minor changes, too: I vertically centered all cells and added a minor edit to one column to avoid a #VALUE error if the wrong order of input values is used.
(Visit the Download page to download the latest version of Statistical PERT – Beta Edition).