ABSTRACT
Real-world problems are usually large and complex. It is not always feasible to include all aspects of reality in the model of a problem. In most cases, we deal with a simplified version of the problem that contains only some aspects of reality. Thus, a problem can be modelled in a number of different ways depending on the portion of reality to be included or excluded. In other words, there may be alternative mathematical models for many real-world problems. So the choice of the most appropriate model needs to be analyzed.
