DEVS Monitor: An X Window system-based debugger for the DEVS-scheme simulation environment

Abstract

An effective testing and debugging tool for simulation modeling must be able to extract the salient characteristics of simulation dynamics and present them in a clear and coherent manner, provide fine-grained control over the execution of simulation, and allow direct manipulation of model state to facilitate hypothesis construction and confirmation. We have designed DEVS Monitor to meet these goals. DEVS Monitor is designed around its graphical display of the dynamic behavior of simulation models. Because models in DEVS-Scheme are object-oriented and hierarchical in nature, DEVS Monitor is able to extrapolate from the structure and behavior of the computer model to the structure and behavior of the conceptual model. Specifically, DEVS Monitor represents a model graphically as a tree, and provides visual feedback to state changes and interaction between model components. We will also discuss other program visualization issues, and evaluate DEVS Monitor's performance.