4 ms·
And it also assumes that the optimal is just as likely as the pessimistic. As anyone who has ever planned anything knows, more things can conspire to introduce
by SixSigma 11y ago
And it also assumes that the optimal is just as likely as the pessimistic. As anyone who has ever planned anything knows, more things can conspire to introduce delay than work out just right enough to make it take less than you excepted.
- jacques_chester 11y agoRight, and there's lots of literature jumping on that and trying to repair it. Yet the original formula outperforms single point estimates. But as I said elsewhere in this thread, my suspicion is that the unpacking effect dominates the "improvement" that's observed and that the particular formula is largely secondary.
- SixSigma 11y agoOh yes, you did say that, sorry. I only responded to your first point and then remembered the second myself. PERT is taught as a time based planning tool but it also has a earned value element. The tools for that have moved on too. https://en.wikipedia.org/wiki/Earned_value_management https://en.wikipedia.org/wiki/Earned_value_management I suppose the unpacking effect does make more sense though, over CPA. "How long will it take?" "6-8 weeks" So what do you put in CPA - 6, 7, 8 ? PERT says 7.