Ralph Keeney wrote an article “Decision Analysis: An Overview” in the journal Operations Research in 1982. It is one of the best expositions on what the field of Decision Science/Analysis actually is.

He first introduces the field as “a formalization of common sense for decision problems which are too complex for informal use of common sense.” The problems that require formal decision analysis methodologies to arrive at a good answer are typically big and messy: many stakeholders, competing objectives, subjective valuations of alternatives, various levels of risk tolerance, and hazy projections. In these situations, four steps are needed:
1. Structure the decision problem
2. Assess possible impacts of each alternative
3. Determine preferences (values) of decision makers
4. Evaluate and compare alternatives

Toward the end of the longish (30+ page) article is this beautiful paragraph:

“Decision analysis embodies a philosophy, some concepts, and an approach to formally and systematically examine a decision problem. It is in no way a substitute for creative, innovative thinking, but rather it promotes and utilizes such efforts to provide important insights into a problem. Philosophically, decision analysis relies on the basis that the desirability of an alternative should depend on two concerns: the likelihoods that the alternative will lead to various consequences and the decision maker’s preferences for those consequences. Decision analysis addresses these concerns separately and provides the logic and techniques for integrating them.”

It is a great article for the layman or young analyst and highly recommended.