Operations research (OR) decision theory focuses on applying mathematical and analytical methods to help decision-makers choose optimal solutions in complex scenarios. It deals with the systematic analysis of decisions under various conditions, such as certainty, risk, and uncertainty. In decision theory, various models and criteria are used depending on the available information and the nature of the decision environment. For instance, under certainty, all outcomes are known, while under risk, probabilities are assigned to different outcomes. In uncertain environments, probabilities may be unknown, and decision-makers rely on criteria like Maximin, Maximax, Hurwicz, and Minimax Regret to make informed choices. Operations research employs techniques such as linear programming, game theory, and simulation to model real-world problems, aiming to maximize efficiency, minimize costs, and improve decision-making processes in areas like resource allocation, logistics, and production.