Operations Research (OR) is a scientific method of providing a quantitative basis for decision making.
Operations Research as we know it today is primarily an out-growth of military research in World War II that sought optimal ways to allocate scarce resources. This included questions such as "How should patrol aircraft be deployed to maximize the expected number of enemy submarines detected in a limited number of hours of search?" and "How should a limited inventory of spare parts be distributed among units in the field, advance depots, and distribution warehouses to minimize equipment down-time due to parts shortages?" At the end of the war, most operations researchers moved into industry, where similar questions in budgeting, planning, marketing, decision-making, and other aspects of management were in need of answers.
What should one study in college?
The major mathematical tools of OR are vector calculus, linear algebra, differential and difference equations, probability, statistics, and computer programming. Other courses particularly relevant to this field include number theory, abstract algebra, graph theory and combinatorics. Still other relevant courses may be given in or outside of the mathematics department, e.g., linear programming, control theory, integer programming, dynamic programming, game theory, and queuing theory, as well as computer science courses and simulation.
An individual with a bachelor's degree in mathematics and an applied science minor can possibly obtain direct employment in operations research, but a master's degree in OR is the credential preferred by most employers. A good working knowledge of economics, finance, and organization theory is also valuable, and that is something that a mathematics undergraduate can pursue, perhaps as a minor.
Careers in Operations Research, by the Institute for Operations Research and the Management Sciences (INFORMS)