DEVS-based Formalism for the Modeling of Routing Processes

Abstract

The Discrete Event System Specification (DEVS) is a modular and hierarchical Modeling and Simulation (M&S) formalism based on systems theory that provides a general methodology for the construction of reusable models. Well-defined M&S structures have a positive impact when building simulation models because they can be applied systematically. However, even when DEVS can be used to model routing situations, the structures that emerge from this kind of problem are significant due to the handling of the flow of events. Often, the modeler ends with a lot of simulation models that refer to variants of the same component. The goal of this paper is to analyze the routing process domain from a conceptual modeling perspective through the use of a new DEVS extension called Routed DEVS (RDEVS). The RDEVS formalism is conceptually defined as a subclass of DEVS that manages a set of identified events inside a model network where each node combines a behavioral description with a routing policy. In particular, we study the modeling effort required to solve the M&S of routing problems scenarios employing a comparison between RDEVS modeling solutions and DEVS modeling strategies. Such a comparison is based on measures that promote the capture of the behavioral complexity of the final models. The results obtained highlight the modeling benefits of the RDEVS formalism as a constructor of routing processes. The proposed solution reduces the modeling effort involved in DEVS by specifying the event routing process directly in the RDEVS models using design patterns. The novel contribution is an advance in the understanding of how DEVS as a system modeling formalism supports best practices of software engineering in general and conceptual modeling in particular. The reusability and flexibility of the final simulation models, along with designs with low coupling and high cohesion are the main benefits of the proposal that improve the M&S task applying a conceptual modeling perspective.