We provide a review of different approaches to linking model structure to observed behaviour with a particular view towards using models for theory building. We argue that theory building cannot be based upon pure simulation and model building alone: the inference from system dynamics models invariably uses concepts and analogies from simple feedback systems and models. Strengthening the analytical foundation for this inference will therefore have a direct impact on the strength of system dynamics as a theory‐building tool. We identify four approaches to establish this link (traditional, pathway participation, eigenvalue and eigenvector), assess the strengths and weaknesses of each approach, and point to challenges and tasks ahead. We find that the eigenvalue and eigenvector approaches carry significant potential but that a more solid theoretical foundation of the method is required. However, since a ‘grand unified theory’ will never be possible, all tools will be based on approximations and it is only in their practical use that we can discover their real value.