OR began during World War II when the British government conscripted scientists from various disciplines to work on problems of military operations, hence the name operations research. The goal was to combine purely technical research and operational research. One of the first tasks of these scientists was to develop methods for effectively utilising new defense technologies, such as radar. Air Chief Marshal (later Lord) Hugh Dowding directed this project for the Royal Air Force Fighter Command in England in 1938. The Battle of Britain, fought in July, August, and September of 1940, was the first Allied victory in World War II, and OR applications clearly contributed to the victory. With the U.S. entry to World War II in 1942 several groups of OR scientists were also established in the United States.
After the war there was a recognition by the OR scientists in both Britain and the US that the methodologies developed in a military context had potential for civilian applications and OR departments were established in a wide range of companies and government departments. Similar developments took place in France and other European countries and by 1970 OR was established in most OECD countries, and a number of other countries in Asia, Africa and South America.
The field has developed both in depth and breadth since the early post-war years. By the early 1970's, researchers had developed large bodies of theory and methods such as linear and dynamic programming, queuing theory, game theory, network analysis, replacement and inventory theories, scheduling, simulation, and others. However, within most succesful OR departments the original multidisciplinary approach has been retained and the OR practitioner must always remember that every technical problem is embedded in an organisational context which has to be understood if his or her work is to be effective.