Research And Implementation On BOM-based Modeling Technology For Parallel Discrete Event Simulation

Because of the advantages of running efficiency, the Parallel Discrete Event Simulation (PDES) is being more and more widely used in domains of modeling complex systems. However, in large and complex system, there are often more than entity state changes, the complex interaction among entities and other issues, making the user describe entity models of PDES more difficultly. Base Object Model(BOM) as a component-based standard, provides an effective means for describing the state changes of entity and event interaction among entities, but the research of BOM mainly concentrated on the areas of distributed interactive simulation, and there is no research on how to use the means which BOM provided to characterize the entity state changes and event interaction in PDES. Therefore, the study on BOM-based modeling technology for PDES becomes an important issue, to meet the demand of describing entity model in large-scale complex systems and improve the ability of the overall design of complex systems.According to the characteristics of complex system, this paper in-depth analyzed and researched BOM-based modeling techniques for PDES. Major work and innovation include:1. In PDES, state transition reflects the change of entity state. Current description of state transition is either too abstract and reduce accuracy of model, or too formal and difficult to directly reflect state change, which affected the model development at a certain extent. To resolve this problem, the paper puts forward a graphic representation of state transition of PDES based on BOM state machine, through combining state diagram and state table, this method provides graphics and tables for displaying states,transitions,actions, so the behavior of entity can be describe visually, and the accuracy of model can be promised.2. Event Graph is one of main approachs for describing event interaction between entities in PDES, but the events and relationships that can be described by Event Graph is relatively simple, limited information can be captured by developer. To resolve the problem, the paper proposes a graphic method based on BOM pattern of interplay to describe the interaction among PDES entities, the method reflected relationships of entities in event scheduling by sequence diagram, and provide event scheduling table to represent correlative information exactly. So users can effectively describe the complex interaction among entities by an easy and intuitive means.3. When combining BOMs to create a new model, matching BOM state machines is a very important step. Existing works need to translate BOM state machine into other languages, then running on corresponding state machine emulator, and returned the run results, which increased time cost of matching at a certain extent. To resolve this problem, a novel mechanism of matching state machines was proposed. The mechanism designed a customized data structure for storing information of state machines, and can matching state machine directly without format conversion, through an action send-port or receive-port the transfer between states was triggered, this makes the process of matching more efficient.Based on the above research results, the paper designed and implemented a BOM-based visual PDES modeling tool. The tests show that the tool is simple to use, easy to operate, and can effectively support the user to describe state changes and event interactions in PDES expediently.