All decision making starts with a domain and context. Without domain and context we have no way to understand the environment in which we operate and the well defined objectives needed to assess our decision making process. We have no way to address the natural uncertainty of our project work. We can not make a decision in the absence of alternatives.
We can only address uncertainties - both reducible and irreducible - by understanding the probabilistic outcomes created by the underlying statistical processes. Assessing the resulting outcomes against our goals is the basis of all probabilistic estimating and forecasting activities of any credible decision making processes.
It is the probabilistic and statistical information that informs our decisions. To ignore this means we are driving in the dark with our head lights off.