Operations Research uses the methods of science to understand and explain the phenomena of operating systems. It devises the theories( models ) to explain these phenomena uses these theories to describe what takes under altered conditions and checks these predictions against new observations. Thus, " Operations Research is a tool employed to increase the effectiveness of managerial decisions as an objective supplement to the subjective feeling of the decisions maker."

For instance in distribution or allocation areas, O R may suggest teh best locations for agencies warehouses as well as the most economical kinds of transportation in marketing areas it may aid in indicating the most profitable type use and size of advertising campaigns in regard to available financial limit. O R may suggest alternative courses of action when a problems is analyzed and a solution is attempted. However the study of complex problems by O R techniques becomes useful only when a choice between two or more courses of action is possible.

O R may be regarded as a tool that enables the decision maker to be objective in creating alternatives and choosing an alternative which is best from among these.