Hi kychan,
thank you for your emotional topic.
I really appreciate it.
Decision making is more and more rational. (science oriented)
Because you have to rely more and more on data, on model, and real time feedback etc.
On the other hand, it also rely on intuition. (art oriented)
Because your framework of handling information is normally customized for different scenarios.
There is no manual, only Concept.
In summary, decision making is the combination of rational deduction and pop out intuition.