On the Validation of System Dynamics Type Simulation Models

Simulation models in general and system dynamics type simulation models in particular have become increasingly popular in the analysis of important policy issues in business organizations. The usefulness of these models is predicated on their ability to link patterns of behavior of a system to the underlying structures of the system. Despite their capabilities, the acceptance of system dynamics simulation models by the broader community of modelers and decision makers is limited. We argue that reluctance by the system dynamics modelers to expose their models to formal validity procedures is the main problem. This leads to an exploration of formal validity procedures available but less explored in system dynamics modeling ´repertoire´. An illustration of the application of tests for both the structural and behavior validity of a system dynamics simulation model follows. Finally, some conclusions on the increased appeal for simulation models for the wider community of model builders and users are drawn.