Two important classes of information systems, Workflow Management Systems (WfMSs) and Enterprise Resource Planning (ERP) systems, have been used to support e-business process redesign, integration, and management. While both technologies can help with business process automation, data transfer, and information sharing, the technological approach and features of solutions provided by WfMS and ERP are different. Currently, there is a lack of understanding of these two classes of information systems in the industry and academia, thus hindering their effective applications. In this paper, we present a comprehensive comparison between these two classes of systems. We discuss how the two types of systems can be used independently or together to develop intra- and inter-organizational application solutions. In particular, we also explore the roles of WfMS and ERP in the next generation of IT architecture based on Web Services. Our findings should help businesses make better decisions in the adoption of both WfMS and ERP in their e-business strategies.