Operations Research is the discipline of applying advanced analytical methods to help make better decisions. By using techniques such as mathematical modeling to analyze complex situations, operations research gives executives the power to make more effective decisions.
OR is the application of scientific methods, techniques and tools to problems involving the operations of system so as to provide these in control of the operations with optimum solutions to the problem.
The main origin of OR was during the second world war. At that time, the military management in England were having very limited military resources, it was necessary to decide upon the most effective utilization of them, e.g: the efficient ocean transport, effective bombing etc.