ABSTRACTThis paper discusses an emerging development methodology, Performance Support Engineering, that can be used to design and build performance support systems. It introduces a new model called the Organizational Performance/Learning Cycle that describes the dynamics of the organizational learning process and provides a framework for thinking about the technologies (Ariel 1994) and methodologies that enable that process. The author argues that previous definitions of EPSS were too limited and restricted in their scope and expands on these earlier definitions to take into account this new model of organizational learning. The new dofinition clparly distinguishes EPSS from traditional systems development, which focuses on data, not on knowledge, and from expert systems development, which focuses on knowledge rather than on enabling performance. This new view of EPSS offers a clear opportunity for organizations to recognize the strategic importance of managing their knowledge assets. Most of the current methodologies in use by different functional groups are limited in their capability to enable this model and the expanded definition of EPSS. The author describes how the emerging Performance Support Engineering methodology overcomes those limitations.