Building a simulator with GPSS/H

BUILDING A SIMULATOR WITH GPSS/H Douglas S. Smith Daniel T. Brunner Robert C. Crain Wolverine Software Corporation 4115 Annandale Road Annandale, Virginia 22003, U.S.A. A simulator is a data-driven simulation tool designed for a specific system or type of system. Combining a data-entry front-end with a parametrized simulation model produces a tool which a “non-simulationist” can use to analyze complex systems. This paper provides an overview of the classes of simulation tools, describes the components used to build a custom simulator, details relevant features of GPSS/H, and discusses Wolverine’s new GPSS/H run-time version. 1 CLASSES OF SIMULATION TOOLS Over the past decade, numerous discrete-event simulation systems have emerged. However, “off-theshelf” modeling software can still be classified into two general categories: packages and languages. The primary differences between simulation packages and simulation languages are the model-building interface and the level of detail allowed by the software. The tradeoff is between ease-of-use and modeling flexibility. Packages tend to cover a broad range of specitlc applications, while languages are usually general purpose. A third type of tool, the simulator, has emerged as a means to provide simulation capabilities to users with little or no simulation modeling experience. Simulators are custom-built analysis tools designed by experienced simulation model builders. They are used to analyze a single system or a narrow range of specific systems. Many of the software products that have been referred to in the past as simulators are more appropriately called packages. Packages include a model-building interface which may expedite the modeling process but still requires the end user to know how to design simulation models. Simulators, on the other hand, require no model building by the end user. The parameterized model that is used in a simulator is designed and built by an expert and is driven only by data supplied by the end-user.