Is decision-making art or science?
We are accustomed to making task lists, notes if more details are needed and visualize workflows or concepts using whiteboards.
But visual aids like whiteboards and flow diagrams only depict the visual helpers for understanding the parameters, not a solution for predicting outcomes.
An important concept to add to this methodology is to include probabilities for each possible outcome and develop a decision tree.
Managing a project (mostly on timeline and features vs. quality considerations) is different from making decisions. It may not look familiar initially, and the way outcomes are presented could be counter-intuitive, too.
But once you start to think things in a probabilistic way, you'll gain confidence in this approach. Evaluating as probability changes with time-lapses and reviewing the outcomes to improve the system will eventually allow you to set up a reliable decision-making system that eliminates guesses and doubts.