Decision analysis is a formal, structured, systematic and visual approach to evaluating problems that leads to decisions and action. It utilizes a range of methods, models and tools to aid in the capture, analysis and synthesis of qualitative and quantitative information that is germane to the issue at hand.
You can utilize decision analysis at different scales---from personal decision-making to long-range international policy planning. Tools commonly used by decision analysts include decision trees, game theory, statistical modeling and simulation.