Operation reac Involves the use of mathematical models, equations and similar other mathematical expressions. Assumptions are always incorporated in the derivation of an equation or model and such an equation or model may be correctly used for the solution of the business problems when the underlying assumptions and variables in the model are present in the convening problem, if this caution is not given due care then there always remains the possibility of wrong application of O . R. Techniques. Quite often the operation researchers have been accused of having many solutions without beings able to find problems that fit.