On the qualitative properties in system dynamics models

This paper proposes that the concept of 'qualitative' developed around the qualitative theory of nonlinear dynamical systems be applied to the field of system dynamics in order to provide a more solid foundation for the use of the qualitative in this field. The advantages of the use of qualitative concepts are ana- lyzed both from a conceptual and an operational point of view. A preliminary stage in the world modeling process is used to illustrate this proposal.