The process view of simulation in Ada

• Authors: Greg Lomow;Brian Unger
• Venue: WSC '82 Proceedings of the 14th conference on Winter Simulation - Volume 1
• Year: 1982

Previously, the process view of simulation, which represents a model as a set of competing and cooperating entities, had been most successfully implemented in the general purpose language SIMULA. This paper describes such a system which is currently being implemented in ADA. ADA's suitability as the base language for such a package is first discussed followed by a description of the facilities offered in SAMOA. (Simulation and Modelling on Ada). SAMOA is a fully integrated, general purpose, discrete event simulation package whose features are illustrated through the use of examples. The process view is a simple and natural way to define discrete event simulation models. This follows from the fact that a broad range of natural human-made systems can be easily described in terms of interacting concurrent processes [2], [7], [9], [20]. Models defined using this process approach are very similar to natural language descriptions of the actual systems being modelled. In fact, the process view has been used in the DELTA Language to structure system descriptions which are intended solely as aids for human communication about systems [8]. The SIMULA [5] programming language provided an early implementation of the process approach to simulation. This general purpose language was designed to enable the definition of abstract types in terms of both primitive types and other abstract types. These abstract types can include actions so that instances, or objects, of these types are pseudo concurrent autonomous processes.