Purpose System dynamics is a whole-system modelling and learning approach, useful for tackling non-linear problems, such as sustainable urban development. The purpose of this paper is to review system dynamics applications in the simulation of sustainable urban development over a period from 2005 to 2017. Design/methodology/approach The analysis reveals that the number of applications of system dynamics modelling in the area of urban sustainable development increased in the analysed period. Research has changed its focus from the modelling of environmental problems to more complex models, portraying the multidimensional socio-economic processes that have an impact on the sustainability of urban development. Analysed case studies most often use the behaviour reproduction test for model validation, but without a unified approach. In most cases, modelling has been done in China, Germany and the USA, while urban development in the Eastern European countries, Africa and Latin America has not often been investigated. This paper indicates the knowledge gaps and suggests future research directions. Findings Papers that report the use of system dynamics modelling reveal a wide range of applications in urban sustainability. The analysis shows significant emphasis on environmental problems, while the interest for modelling social problems has been increasing during the last several years. Most of the modelled problems examine the sustainability of resources (land, water) and waste management, which are used for insights into the reasons for the system behaviour, forecasting future behaviour and policy testing. Originality/value The presented models were developed in most cases for the purpose of understanding the phenomena examined, as well as the future use of the models in policy planning. This brings us back to the need for greater stakeholder involvement, not only in the initial phase, but also during the whole modelling process, which could increase understanding, use and ownership of the models in the future, and thus increase their practical application.

Abstract. In line with global trends, the Croatian military is currently going through a transformation, but is being stifled by a long recession and negative demographic trends. The purpose of this article is to outline the possibilities of applying system dynamics models in testing the sustainability of the Croatian military forces (CMF) with respect to their size and composition. The article mainly focuses on the demographic trends and their implications on the CMF. After a brief exposition of the research done in this field to date, the article presents two developed models -a demographic model and a military recruitment model. The models were carefully tested using validation tests suitable for system dynamics modelling. Subsequent to validation, the models were merged into a single integral system dynamics model of the CMF. Three experiments were conducted based on different fertility values, and the impact of demographic trends, which emerge from the different fertility levels. The results of the simulation, based on demographic data from the 2011 Census, as well as estimated data, though not accessible at the time, suggest that the Croatian military will encounter difficulties in meeting its demands for recruits in the next 20-30 years. Further implications of current demographic trends on the CMF's sustainability are discussed towards the end of the paper. Since basic inputs for any organization are labor and capital, the problem is addressed from two complementary perspectives: a demographic and a financial perspective.