Training for assembly simulations can be provided using a wide range of technologies from a simple computer-based training (CBT) approach to a complex virtual reality (VR)-based immersive training (IMT) approach. The CBT approach allows user interactions through traditional keyboard and mouse applications, while the IMT approach immerses the user in a virtual environment for a more realistic experience. Typically, for a particular scenario, tools and applications for each of these approaches are developed independently. Consequently, there is much duplication of data and effort, and a lack of synchronization between them. This paper focuses on an integrated approach with support from ontologies to address this problem. Ontologies provide an opportunity to capture and manage common data and map concepts from one application to another in a logical and measured manner. Methods are developed to enable knowledge in these ontologies to be used and shared in a comprehensive and effective manner between CBT and IMT tools. The key contribution of this work is that the ontologies instantiating concepts and properties for the training domain are used effectively among different training tools to deal with common and disparate characteristics between them.