Principles of modeling (panel)

The time has come for the simulation community to explore, or some would say re-examine, the fundamentals of modeling and models. By modeling is meant the process of building a model where a model is a description of a system. Most aspects of simulation activity involve modeling and models. Throughout the simulation community, there would be close to unanimous endorsement of the following statement by Simon (1990) “Modeling is a principal — perhaps the primary — tool for studying the behavior of large complex systems. When we model systems, we are usually (not always) interested in their dynamic behavior. Typically, we place our model at some initial point in phase space and watch it mark out a path through the future.” Even with unanimity of agreement on modeling as a principal tool, only a small amount of research is directed to identifying underlying principles, foundations, or fundamentals of modeling as related to simulation. This panel has been established to promote a greater exploration of modeling principles. The panel has decided to be heroic and present their basic thoughts on modeling principles. In doing this, we decided not to be bogged down by questions relating to what constitutes a principle or to be concerned during this first panel withthe formal definitions of modeling and model. Basically we are looking for directions through which we can establish modeling principles which are acceptable to the simulation community. We recognize that the current state of affairs is a chaotic one. Hopefully, by brainstorming in the panel through direct questioning of each other and through audience participation, a better understanding of what is meant by a modeling principle and how it should be presented or stated can evolve. Our criterion relating to the value of a modeling principle is its acceptability to members of the simulation community. The form used for this paper is to have each member of the panel present “principles” and give brief discussions and/or justifications for each principle. A principle can be a guideline, an orientation, or a fundamental characteristic associated with modeling and models. Audience empowerment is envisioned through invitations to be members of future panels on principles of modeling if they are thought to be necessary (probably deemed to be so a priori) and thought to be useful (which may not be as easy to evaluate). The panel starts with a clean slate and the assumption that there are no established, published principles of modeling. It is assumed that all modeling principles presented have been developed based on the panelists experience and interaction with colleagues. A naming convention (panelist’s initials and number) in this paper is employed for ease of reference during the panel.