American baseball player Yogi Bera is well known for his witticisms, among them "When you come to a fork, take it". And, for project managers this means when you come to a probabilistic branch in the schedule, it's decision time.
The problem is: on paper it always looks like that there is plan for a decision to be made for which there's freedom of choice; whereas sometimes your hands are tied, your options have become limited, or the situational logic for one thing over another is overwhelming.
A biggie in this regard is time. Sometimes, we just run out of time to take the 'A' course despite its better strategic fit, the only practical choice then being 'B'. (Maybe we can't do 'A' if we can't make the decision before September 1st, as an example.)
Thus, we empathize with B.L. Hart when he explains:
Basil Liddell Hart
How frustrating! The logic is on our side; the 'facts' seem to be on our side, but still we are compelled by circumstances to decide the other way.
This sort of stuff gives probability analysis and decision analysis a bad name, because in the end, the decision wasn't probabilistic at all; indeed, it really wasn't a decision.
We were propelled by the exigencies of the moment.
We had no choice!