Detecting logic errors in discrete-event simulation: reverse engineering through event graphs

Several inherent constraints remain in the model development process, even though modern enhancements to simulation environments have provided tools for code generation, debugging, and tracing. To develop a simulation model, the simulation analyst still needs to have expertise in a number of different fields, e.g., probability, statistics, design of experiments, modeling, systems engineering, software engineering, and computer programming. Although several simulation packages implement syntactic-checks and semantic-consistency-checks, typically, the simulation analyst needs to possess output-analysis-knowledge specifically aimed at verifying and checking the simulation code.Reverse engineering a graphical model, e.g., an event graph, from general purpose simulation code demonstrates an enhancement to the model development process. A reverse engineering step allows an analyst to check, both, the static and dynamic properties of the coded simulation model. Even though the reverse engineering produces an event-oriented view, the enhanced model development process provides a systematic approach for conversion from other world views. Overall, this enhanced process provides a framework which yields better analysis techniques.Better diagnostic assistance is achieved when viewing a combination of static and dynamic properties of the simulation code. Now, the analyst is able to find logical/execution errors, e.g., errors related to resource deadlocks, before running simulation experiments. Since the graphical model is generated from the simulation code, and the process combines views, the analyst also has a better framework for verifying the coded simulation model. Also, the reverse engineering step provides a structural model useful in converting between different simulation languages or systems. Improvements to the techniques for conversion between languages will facilitate reuse of existing programmed models.