ABSTRACT
Sometimes a deterministic linear and static model may abstract a real problem. Such models are generally simpler than the corresponding stochastic, nonlinear and dynamical models. Essentially most realistic models are nonlinear, dynamic and stochastic. However, linear and static models are used as simpler models that can be easily handled and give good approximation to the real problem. Similarly continuous models are preferred over discrete ones. Analytical solutions may be obtainable for continuous models in contrast to discrete models.
