Software and Methodology for the Design of System Dynamics Models Based on the Situation-Activity Approach

An original approach to the system dynamics models' design as a projection of situation-activity analysis, expanding the possibilities of predictive-analytical research, is proposed for consideration. System dynamics models in this aspect are applied to human reasoning with the reference to the specific objects of activity. This makes it possible to establish the specified criteria for assessing the state and trajectory of the development of the system being modeled. This article proves the hypothesis that methods of knowledge representation in situational, expert and system dynamics models are similar. At the same time, the conceptual structures of situation-activity analysis incorporate the tools inherent in the system dynamics language. Conceptual structures are the core of the design of system dynamics models in notations: levels and flows. The result of the situation-activity design is a model represented in a conceptual language of knowledge representation, where the basic element is the act of doing. The conceptual structures of activity acts can be used to build production rules for the expert system. However, it is possible to extract partial representations from the conceptual structures of activity acts: process plans and regularities. On the aggregate of these plans, a graphical image for building system dynamics models is implemented. The knowledge of the fact that constructing conceptual structures is very challenging sparked off different searches for the best way to deal with this problem. Eventually the best solution has become a software toolkit "Designer + Solver + Interpreter which allows one to visualize conceptual structures, implement knowledge bases for expert and system dynamics models, as well as to conduct research on completeness and adequacy of the model.