In the space of two days, I had evolved two plans, wholly distinct, both of which were equally feasible. The point I am trying to bring out is that one does not plan and then try to make circumstances fit those plans. One tries to make plans fit the circumstances.
—George Patton
Plans are strategies. Strategies are hypotheses. A hypothesis requires experiments to confirm or deny the conjecture.
In project management, the hypothesis that the plan, cost, schedule, and technical performance are adequate to deliver the needed capabilities must be tested at an interval sufficiently in time to take corrective or preventive actions to increase the probability this will actually happen to a sufficient level to assure those paying for the work, they'll get what they're paying for when they need it for the needed cost.
To make those assurances, estimates are needed of the Epistemic (reducible) and Aleatory (irreducible) uncertainties that create risks to project cost, schedule, and technical performance success.
#NoEstimates willfully ignores these principles of managing in the presence of uncertainties.
