The document discusses various concepts and approaches related to operation research and decision making under uncertainty and risk. It defines operation research and provides characteristics and scope of OR, including areas such as allocation, production, procurement, marketing, finance, and personnel. The methodology of OR includes problem formulation, model construction, solution, testing, and implementation. Decision making environments like certainty, uncertainty, and risk are explained. Approaches for decision making under uncertainty like maximax, maximin, minimax regret, Hurwicz, and Laplace criteria are illustrated with examples. Decision making under risk assumes state probabilities are known and expected value criterion is used.