Reaction graphs: kinetic cousins of pseudo bond graphs with applications in ecology, epidemiology and socio-economy

As a modelling method in soft sciences, Forrester's system dynamics (FSD) has been both very successful and hugely criticised. The author argues that one of the reasons for the criticisms is that FSD does not capture all the structural aspects of soft systems. The author's claim is that it should now be generalised to a study of all processes isomorphic to abstract chemical kinetics. The author therefore defines a new formalism, the "reaction graphs" allowing that extension. Reaction graphs are both generalisations of FSD and watered-down pseudo bond graphs. By putting all these methods in a unified perspective, the author obtains a complete set of tools to build network lumped models of complex soft systems.