... the level of aggregation depends on the purpose of the system model. The structure of a system is also differently defined in the literature. A structure of a system, in view of systems modelling, ... open system is a system which is not well defined (uncertain parameters, state variables, boundaries, etc.). Examples of open systems are: groundwater systems, social systems, as well as most of ... five different types of integration within the framework of Integrated Assessment Modelling (IAM). These are integrations of disciplines, of models, of scales, of issues, and of stakeholders. Scrase...