The operation of existing infrastructures is often inefficient and subject to failures. When a failure occurs, various stakeholders need to make decisions that are specific to the failure type and bear little resemblance to decisions faced during normal operation. In this work, we demonstrate a model-based approach to making rational decisions in such situations. Agent-based models serve as a suitable paradigm for modelling complex sociotechnical systems. Given the broad similarities between different networked infrastructure systems, an ontology has been developed as the foundation for a 'model factory' for such systems. A specific application of this model factory to a refinery supply chain system is described. Further, the use of this simulation model for decision support to manage an abnormal situation in the supply chain is reported. Copyright © 2009 Inderscience Enterprises Ltd.