# Schema of modelling process

## Formulation of the problem

To get satisfactory results from modelling reality first has to be simplified (Figure1). The formulation of a precise problem is done within two steps of abstraction. While the first one is done unconsciously quasi unrecognisable to ourselves (awareness) the second one is made knowingly (abstraction) to reduce the number of input parameters in a way that leads to the essential and particularly ascertainable variables. Modelling or Model analysis means to understand the features of a model in order to set up equations skilfully and choose appropriate algorithms.

## Numeric & Programming

Solving mathematical equations with an analytical method is quite impossible. However, numerical approximation procedures often lead to the desired solution. The programming of a mathematical based model means the coding in software and the application of appropriate computer languages and tools.

Scheme of the modelling process

## Simulation

Having created a realistic but simplified model of reality and having translated it into a computer understandable language the simulation process can be started, provided that the input data are empirically described or physically known.

## Results

The results from a simulation process are due to be proved via comparison with the reality.

• In case of a good reproduction of reality the simulation can be considered as suitable. Further simulations can be started.
• In case of bad reproduction of reality parameteres as well as the model structure itself should be analysed and adapted where necessary.