Review and structural analysis of system dynamics models in sustainability science

Abstract

Abstract As the complexity of sustainability-related problems increases, it is more and more difficult to understand the related models. Although tremendous models are published recently, their automated structural analysis is still absent. This study provides a methodology to structure and visualise the information content of these models. The novelty of the present approach is the development of a network analysis-based tool for modellers to measure the importance of variables, identify structural modules in the models and measure the complexity of the created model, and thus enabling the comparison of different models. The overview of 130 system dynamics models from the past five years is provided. The typical topics and complexity of these models highlight the need for tools that support the automated structural analysis of sustainability problems. For practising engineers and analysts, nine models from the field of sustainability science, including the World3 model, are studied in details. The results highlight that with the help of the developed method the experts can highlight the most critical variables of sustainability problems (like arable land in the Word 3 model) and can determine how these variables are clustered and interconnected (e.g. the population and fertility are key drivers of global processes). The developed software tools and the resulted networks are all available online.