The models which will be stressed in the class room are those which are currently used in business systems. Each model is a particular representation of reality. Since managers are interested in different parts or cuts of reality, we will focus our attention only on specific aspects of reality. Furthermore, we can call this special delinea tion of reality a system. Therefore, the purpose of a model will be to de scribe , explain and predict the performance of a system.
Models are both substitutions and simplifications of a system.
To be useful a model must reasonably behave like a system, at least in the area and over the range of interest. The model should explain and predict the individual compo nents of a system, the response of the system to changes in its components, and the effect of internal and external disturbances. Also, to be useful, the model must be cost-effective. To understand how to make a good, realistic decision once a model is selected and output is provided. Behavioral objectives usually follow the quantitative objectives and include the development of scientific methodology, interdisciplin ary teamwork, and finally the system approach.