A major characteristic of a DSS and many BI tools(notably those of business analytics) is the inclusion of at least one model.
The basic idea is to perform the DSS analysis on a model of reality rather than on the real system.
A model is a simplified representation or abstraction of reality. It is usually simplified because reality is too complex to describe exactly and because much of the complexity is actually irrelevant in solving a specific problem .
Model can represent system or problem with various degrees of abstraction .
They are classified, based on their degree of abstraction, as icon, analog, or mathematical.