Abstract for: Modular Decomposition and System Integration Using Shared State Variables and Subdivided Time Steps

This paper introduces a modular system dynamics model development method. Existing models can be decomposed or new modules built, each with specific functions and independent operation. Shared state variables and subdivided time steps enable module integration for complete model functionality. This method aims to establish a System Dynamics module library, initiating a 'model factory' concept. To integrate modules, combine them into a single Vensim file with separate views, unify stock and constant names, subdivide simulation time steps, and ensure each stock accepts changes from only one module per sub-step. This enables cohesive model functionality. The feasibility of this method has been preliminarily demonstrated using two published models as examples. By further standardizing module interfaces and functional encapsulation, a methodological framework can be provided for building a 'model factory'. Currently, the process of splitting existing models into modules and recombining them is entirely manual, which increases the likelihood of errors, and the number of existing modules is also relatively low. To establish a module library of a certain scale and use it to build entirely new models, rather than just recomposing existing ones, more software support is needed to achieve at least semi-automation of model decomposition and composition.