ABCmod: a conceptual modelling framework for discrete event dynamic systems

Abstract

The notion of a conceptual model is invariably present in any discussion about the modeling and simulation process within the discrete event dynamic system domain. Unfortunately the notion has an elusive characterization and one might easily get the impression that it is merely a notion and is not, in fact, an actual artefact. The situation borders on the paradoxical in view of the widely acknowledged importance of the conceptual modelling concept. Our intent in this paper is to address this curious situation by presenting a specific framework for the development of conceptual models for simulation studies of discrete event dynamic systems. The framework is essentially a perspective that is supported by a variety of constructs that enable its application within any given problem context. It accommodates, in a common format, both the structural and the behavioural aspects that are fundamental components of any conceptual model. The framework's environment is flexible and adaptable and provides a collection of constructs both for handling input/output and for dealing with special circumstances such as pre-emption interruption and balking. As might be reasonably expected, its constructs can be readily transformed into simulation models (computer programs) within any of the standard world views. We provide an overview of the essential elements of the framework and illustrate some of its features in several example problems.