Continuous execution of system dynamics models on input data stream

This article describes a new approach for system dynamics models execution. In most cases when model execution is involved it is performed on a set of static and known data, which are sent to the model as an input. And it is expected, that on the model output modeler will get a set of other system or event characteristics, computed by the model based on the input parameters. This approach still has the widest usage, but it is not the only one scenario, which is demanded by different industries. With growing popularity of concepts such as Internet of Things, demand in modeling based solutions, which take as input continuous data streams, has grown significantly. In comparison with stand-alone client-side modeling systems, cloud-based solutions, such as sdCloud, became a reasonable answer to such industry request. Such systems can provide an ability of continuous execution of system dynamics models. In other words, these systems are ready to accept an incoming data stream and perform model execution that will result in streaming modeling results back to the end-user. Running system dynamics models in parallel with the process it is describing allows to perform predictive modeling of the system status in the future, and it also allows to find additional hidden external impacts to the model. For example, such approach can be a base for predictive maintenance of complicated technical systems, because it allows computing nearest maintenance time more efficient

Policy Model of Waste Management - Modelling of Shanghai Municipal Solid Waste Management Regulations

Waste management systems have always been considered complex. Scholars have studied waste management mostly from a macro perspective for a long time, considering waste management policies as a fraction of this complex system. This study presents the causal variables and feedback relationships related to waste management from the inside of the policy, using the macroscopic ideas of Environment-Based Design (EBD) and the system dynamics pictorial representation. The policy model developed in this thesis provides a graphical representation of the abstract policy language. The policy system model constructed based on the policy model further clarifies the linkage between policy and waste management systems. The way the policy really works is also clear from the analysis of the results, i.e., the policy controls the entire waste management system by controlling a subset of variables that affect other variables but are not affected by other variables. These variables can be divided into three categories: user-related variables, policy-related variables, and resource-related variables. Along with the analysis of policy statements and the search for policy variables, this thesis investigates the process of policy generation and evolution. The general structure of the policy is linked to the responsibilities and work requirements of the various stakeholders within the policy based on three aspects: master plan, management hierarchy, and legal penalties. These structural maps will work together with the policy model to help policymakers further enhance the comprehension and improve the content of the policy in the future