Although the importance of knowledge sharing among designers has been widely recognized, knowledge about functionality in the conceptual design phase is hard to capture and is often scattered across technical domains. Aimed at capturing such functional knowledge that can easily be applied to other domains, we developed an ontological framework to systematically describe it. It includes six kinds of knowledge about functionality, i.e. two types of functional models, two types of organization of generic knowledge, and two ontologies of functionality. This paper reports on the successful deployment of the framework in a production company. The Plant and Production Systems Engineering Division of Sumitomo Electric Industries has used our framework to share functional design knowledge on production systems