Today I added a new Agile Forecast tab to the forthcoming Version 2 of Statistical PERT Beta Edition. This Agile Forecast tab is very similar to the Agile Forecast tab in the SPERT Normal Edition Version 3. I introduced the Agile Forecast tab last year in Version 2 of SPERT Normal Edition.
What makes the Agile Forecast tab different in the SPERT Beta Edition is that it, obviously, uses the beta distribution to model the uncertainty around what each Scrum sprint (or agile iteration) will accomplish. This opens up the possibility to model this uncertainty using shape parameters that very nearly create a uniform distribution (in SPERT Beta Edition, this is called a “Guesstimate” about how likely the most likely outcome really is).
I compared some results between SPERT Normal and SPERT Beta Editions, and found that both editions calculate the same release date, just in different ways. Notably, I used “Medium-Low Confidence” in SPERT Normal, but had to use “Very Low Confidence” in SPERT Beta to obtain a close match of the standard deviation. By default, SPERT Normal uses only 7 subjective phrases for how likely the most likely outcome is, but SPERT Beta uses 10. The two editions treat the subjective phrases differently, even though they share the same word phrases.