"System Dynamics (SD) is an approach for understanding the dynamic behavior of systems, in particular social systems. These behaviors defy intuitive solutions and attempting to apply ordinary processes of description and analysis leads to inconsistencies and contradictions. Since these systems are made up of multiple, nonlinear feedback loops human mind is not able to interpret how they behave. Consequently, a system's actual behavior differs substantially from its expected behavior."-Systems Concepts in Action, Chapter 2