Organizational learning is currently a subject of intense debate in the study of corporate dynamics. But how can such a concept be used effectively without a thorough understanding of the way in which organizations produce and distribute knowledge? An in-depth analysis of expert system projects afforded a choice opportunity for studying such questions. Drawing on four case studies, the authors identify and explore the dynamics of three basic types of expertise. They simultaneously reveal the crisis in expertise experienced by firms facing the demands of product variety and innovation. In such industrial contexts, organizational and managerial theories clearly have to include new approaches, presented here, which focus on the dynamics of expertise.