Synthesis of design evaluation modules in an object-oriented simulation environment: Methodology, techniques, and prototype.

Abstract

A wide range of modeling and simulation packages have been applied to evaluate computer systems, telecommunication networks, and diverse environments in industry. The objective in utilizing simulation is to assess system designs prior to actual implementation. The approaches used to perform modeling range from programming with a specific simulation description language (the most common) to automation, using an icon-driven user interface. Flexibility, maintainability and acceptability are the main criteria used to make a choice. The objectives of the modeling and simulation environment are to automatically construct simulation models for the systems being designed, and to efficiently define the system performance measures. To meet these objectives, an environment called Performance Object-oriented modeling and Simulation Environment (POSE) has been created. In order to profile the knowledge involved in POSE, a knowledge representation scheme, System Entity Structure (SES) is adopted for efficient representation. POSE is organized into several layers such that the procedures of modeling can be set up in a hierarchical manner with the support of hierarchical model-based management. At the stage of defining system requirements, the structure of the Experimental Frame is applied to handle the system's traffic generation, performance data collection and computation. A methodology called Integrated performance Specification (IPS) is designed to facilitate model generation of the frame structure. At the system modeling level, elementary models are organized via combining the properties of a queuing model and the structure of Discrete EVent System Specification (DEVS) formalism. An overall system model is then constructed based upon the elementary models by applying the SM-Algo algorithm. Finally, the system models are integrated with the proper experimental frames in distributed and centralized execution modes to create integrated simulation models. An algorithm called MI-Algo assists the integration procedure. A window-based graphical front-end offers a simple and straightforward user interface to enhance the efficiency of POSE.