I created one of these tools when I interned at Crystal Ball (before it was acquired by Oracle. On the on hand, it really was as slick as you'd hope - like, sin

I created one of these tools when I interned at Crystal Ball (before it was acquired by Oracle. On the on hand, it really was as slick as you'd hope - like, since we used Project for the calculation engine, and Project integrates with Outlook's calendar, you can see that if Alice is the only one that can complete a task, that task can't be done while she's on vacation, etc. On the other hand, I never had a chance to see it used for real (honestly, I'm not sure it ever was), but I'm not sure it would help. The results are hugely sensitive to the distributions, and the whole point is that even the distributions are difficult to estimate - you just don't know what you don't know.