How to build valid and credible simulation models

In this tutorial we present techniques for building valid and credible simulation models. Ideas to be discussed include the importance of a definitive problem formulation, discussions with subject matter experts, interacting with the decision maker on a regular basis, development of a written conceptual model, structured walkthrough of the conceptual model, use of sensitivity analysis to determine important model factors, and comparison of model and system output data for an existing system (if any). Each idea is illustrated by one or more real world examples. We also discuss the difficulty in using formal statistical techniques (e.g., confidence intervals) to validate simulation models.