Linear Programming

One can say that operations research consists of t he application of sci ent i fi c methods to the complex problems encount ered in the management of large systems. These systems arise, for example, in indust ry , administration and defense. The goal i s t o aid management in the determi nation of policy vi a the use of t ractable models. A model can be defined as a schem at i c description of t he syst em under consideration (which may be a company, a market, a bat t le, or a t ransportati on network, for example) . To be useful , t he m odel must include a representation of the interaction bet ween the syst em elements. An example could be t he m odel of perfect gases. Perfect gases do not exi st , but the concept helps US t o understand the behavior of real gases . Si mi larly, the atomic model helps us to understand t he structure of material. One of t he non-tri vi al problems of opera- tions research i s the choice of an appropri at e model .
For example, sub-at omic particles help in t he underst anding of superconduct i vi t y, but they could result in an unnecessarily complex model for t he behavior of gases if we were in- terested only in the relationship between volume, t emperature and pressure.