In physical science a first essential step in the direction of learning any subject is to find principles of numerical reckoning and practicable methods for measuring some quality connected with it. I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely in your thoughts advanced to the stage of science, whatever the matter may be. - Lord Willaim Thompson Kelvin, delivered a lecture on “Electrical Units of Measurement” to the Institution of Civil Engneers on 3 May 1883
In the presence of uncertainty found in all project work - aleatory and epistemic - estimates are required to make decisions. Without these estimates, any decision is with knowledge of a meagre and unsatisfactory kind. This is a basic principle of Microeconomics of Decision making, where scarce resources are always present, uncertainty exists for both the outcomes and the inputs needed to produce that outcome.
To suggest that decision can be made without estimates is a fallacy, uninformed by Managerial Finance, Behavioural Economics, and Microeconomics of decision making. To believe you can make those decisions without estimates is he be sold a pig in a poke
