Article ID: | iaor201112729 |
Volume: | 27 |
Issue: | 4 |
Start Page Number: | 358 |
End Page Number: | 373 |
Publication Date: | Oct 2011 |
Journal: | System Dynamics Review |
Authors: | Mojtahedzadeh Mohammad |
Keywords: | simulation: analysis, control, control processes |
Real-world concepts can be operationalized into a variety of feedback structures which may be mathematically identical but diverse in the number of feedback loops. Factors including model purpose, the modeler's perspective and the intended audience all influence the final layout of a feedback-rich model. One challenge in the analysis of model behavior is to account for the variations in the appearance of its structure and the feedback loops. This technical paper focuses on consistency in explaining model behavior and illustrates some of the issues related to the cancellation problem and figure-8 loops. Both conditions can potentially lead to poor and even contradictory explanations of model behavior based on its idiosyncratic feedback structure. The paper presents three case studies and demonstrates that for these case studies the pathway participation approach remains consistent in detecting the dominant structure regardless of variations in the number of feedback loops in mathematically equivalent models. The paper calls for comparative studies using alternative approaches to model analysis to better understand the general principles and subtleties in connecting the structure to the behavior and explaining observed dynamics.