Data coupling and downcasting in discrete event simulation software

Discrete Event System Specification (DEVS) simulation libraries commonly make use of indirection and, essentially, typeless events as part of their interface specification. This forces library users to employ downcasting and/or strong data coupling in the design of their simulation applications. These techniques are anathema to good object oriented design principles, but seem to be inescapable when using pre-built discrete event simulation libraries. This paper describes how downcasting and data coupling emerge in the design of a computer architecture model. It is hoped that, by exposing the problem and its underlying causes, future research can be directed at improving software engineering techniques for DEVS simulation software.