In design science research in information systems (DSRIS), validation is often neglected in exchange for an emphasis on evaluation. However, rigorous scientific contributions most often explicitly address validation. In order to address the complexity of validation within design science, an explicit recognition of the assumptions and methods used within the DSRIS framework is needed. In this paper we discuss an approach to validation in a research in progress aimed at theory development in coordination of crisis response, through the use of agent-based simulation. This enables validation to be discussed from the point of view of simulation, the agent-based approach and the domain of crisis response, underpinned by a hermeneutical epistemology. Other research endeavors within DSRIS can follow a similar strategy to deal with the issue of validation.