Representing Reasoning/Logic in System Dynamics Models

This paper intends to fuel a thought about representing and extracting reasoning in System Dynamics models. A perspective on the flow of information as policies in the system and also flow of information as logic or reasoning in the model is discussed. It also discusses how influences in the model are implemented as rate equations and challenges the impossibility in deriving these rate equations from the qualitative model. This paper raises concerns that the qualitative SD model normally describes the principle behaviour of the system in dual mode whether a growth or decline and omits the structure of reasoning in the model. Finally this paper argues that the logical structure of policies, if effectively represented at the formulation stage would open a channel for a revived and renewed process of developing SD models