During World War II the allies faced many complex problems and to overcome these problems operational research teams were set up, consisting of mathematicians, physicists and other scientists, who pooled their knowledge to solve problems. After the war, their ideas were applied to industrial problems which were previously unsuccessfully solved by conventional means. With the aid of the electronic computer, these procedures became known as the "management science" school relying heavily on quantitative methods.

The contribution of the quantitative school was greatest in the areas of planning and control. However, many doubted the ability of this school to deal effectively with "people." The techniques in this school consisted of capital budgeting, production scheduling, optimum inventory levels and development of product strategies

The management science school differs from the classical and behavioral schools in the following ways:

• The classical or scientific management approach concentrates on the efficiency of the manufacturing process. The management science school places greater weight on the overall planning and decision-making process. Technical efficiency is merely seen as a tool instead of an end in itself;
• It relies heavily on the use of computers and mathematical models in planning;
• It is focused on the evaluation of effectiveness of models like the techniques of the use of models in managerial decision making: the return on investment analysis for example. .

In essence, by using computers and quantitative analysis techniques, the management science school has made it possible to consider the effect of a number of variables in organizations which may otherwise have been overlooked. It must be emphasized that statistical evidence alone may not be sufficient to solve various management problems. The more comprehensive techniques of the behavioral school or the administrative management approach may still be needed to complement. Especially the behavioral school has the ability to look at the welfare of staff and can identify the reasons behind certain behavior.

The scientific, administrative management science and behavioral approaches are useful in different circumstances, but it is difficult to be sure which one is right in a given situation. The systems and contingency approaches may provide a more complete integrated approach to the problems of management.