Event Modeling

Abstract

The purpose of this chapter is to discuss conceptual event modeling within a context of information modeling. Traditionally, information modeling has been concerned with the modeling of a universe of discourse in terms of information structures. However, most interesting universes of discourse are dynamic and we present a modeling approach that can be used to model such dynamics. The Unified Modeling Language (UML) is based on the following notion of an event. “An event is a noteworthy occurrence that has location in time and space. It occurs at a point in time; it does not have duration. Model something as an event if its occurrence has consequences.” (Rumbaugh, Jacobsen et al. 1999). This definition emphasizes that an event occurs at a point in time and that its occurrence has noteworthy consequences. We characterize events as both information objects and change agents (Bækgaard 1997). When viewed as information objects events are phenomena that can be observed and described. For example, borrow events in a library can be characterized by their occurrence times and the participating books and borrowers. When we characterize events as information objects we focus on concepts like information structures. When viewed as change agents events are phenomena that trigger change. For example, when borrow event occurs books are moved temporarily from bookcases to borrowers. When we characterize events as change agents we focus on concepts like transactions, entity processes, and workflow processes.