This paper aims to provide a synopsis on the design science of agent-based modeling and how to adapt an agent-based research strategy for the scientific study of complex business systems. Research in information systems (IS) has begun to advance knowledge in the use of agent-based systems as a means to seek different computational explanations for business phenomena that have eluded scientific inquiry reliant on traditional, specifically, law and axiomatic explanation (Kimbrough, 2003). The focus on business problems requires a different research approach than what is successful in computer science. One key modification is to make instrument validation explicit. This chapter extends a discussion of emerging insights on the subject to ensure the rigor of management science research in agent-based IS (Schlueter Langdon, 2005a).