Research On Conceptual Modeling Of Parallel Discrete Event Simulation

Conceptual models, which act as the communicative model among the domain experts, modelers, developers, and testers involved in the simulation study, can specify the simulation requirements and represent them in a consistent and understandable manner. Conceptual modeling is an important activity in the process of simulation development. Parallel discrete event simulation (PDES) adopts event-driven execution, and is different from traditional distributed interactive simulations in model development and execution model. The existent conceptual modeling methodologies that suited to distributed simulations can not satisfy the conceptual model requirements of PDES. So, the research of PDES conceptual modeling, and exploring effective conceptual model representation and modeling methodology are very important to make simulation requirements more understandable, enhance the efficiency of simulation development and testing, and even take better advantage of PDES in all application domains.According to the characteristics of PDES modeling, this thesis analyes and researches the key technologies of PDES conceptual modeling based on the extant literature on conceptual modeling.Conceptual models can express modeling requirements, and achieve agreement among people involved in the simulation study. The Base Object Model (BOM) standard describes the conceptual elements and their relationships from both static and dynamic views. This thesis proposes a methodology of PDES conceptual model representation based on BOM whose conceptual model definition is used to represent PDES's conceptual elements. The model mapping between conceptual models and simulation models is also provided. With this the simulation requirements could be represented understandably and the simulation models could be developed under right guidance.The thesis extends the BOM's conceptual model definition to satisfy the particular requirements of PDES. The PDES modeling needs complex data type information, so dynamic data types and complex data types which can be further customized by modelers are added. The flags of initialization, input/output, and publish/subscribe are also added to the BOM standard. With the BOM extension, the conceptual models of PDES can be expressed in a more understandable manner and more useful to PDES modeling.Based on Pace's conceptual modeling framework, this thesis proposes an improved workflow of PDES conceptual modeling. There are four basic iterative stages in the development of PDES conceptual models, which include Authoritative Information Collection. Identify Simulation Elements, Develop Conceptual Entities and Events, and Design State Machines and Pattern of Interplay. A case study is used to show how to develop conceptual entities, events, state machines, and pattern of interplay, providing useful guidance for conceptual modeling. The experience and lessons learned from practice are also provided.SUPE-CMD, a conceptual model development tool, and a conceptual model repository are designed and implemented to verify the BOM-based PDES conceptual modeling. As an important part of YH-SUPE, which is a parallel discrete event simulation environment, SUPE-CMD supports BOM-based conceptual modeling by providing table and graphic modeling interface, with which conceptual models can be developed efficiently. The conceptual model repository facilitates the reuse of conceptual models. The results of software test and application proves the feasibility of the BOM-based PDES conceptual model representation and modeling methodology. The SUPE-CMD tool and conceptual model repository can provide effective and efficient supports to PDES conceptual modeling.