Most current practical methodologies and workflow systems for service composition and workflow creation in e- Science pursue a semi-automatic way to allow users to discover and select appropriate services to include in a workflow based on semantic and conceptual service definitions. However, few of these approaches consider the potential for reuse: to share the knowledge gained during the service composition process and to reuse complete or partial of existing workflows. We believe that providing a capability for reuse of this knowledge and workflows could be an important component in a workflow system. In this paper1, we present a methodology and an enhanced system design to facilitate the reuse of knowledge and workflows. It contains a hierarchical workflow structure representation, knowledge management and knowledge discovery components to capture and manage the reusable information in a system, and an approach for using a graph matching algorithm to discover similar workflows.