Product Platform Planning is an emerging philosophy that calls for the planned development and deployment of families of related products. It is markedly different from the traditional product development process, which focuses on optimized designs for individual products. This is a relatively new development in engineering design, which is not typically a part of an engineer's education. Furthermore, it is different from traditional engineering topics in that it requires an integration of principles from both management and engineering design. All this makes for a new and different topic for which educational material needs to be developed. To address these needs, an online resource has been developed, This resource includes a set of three cases, a tutorial, and a glossary in a multimedia format hosted on the Internet. The tutorial developed for the website presents the basic concepts as well as current research on planning and architecting families of products, The case study section has three cases based on a family of popular power tools. The cases present information in the form of function diagrams, assembly diagrams, customer needs and market-segment data. Links are provided to helpful sites, as well as to relevant sections in the tutorial. Although product platform planning is a relatively new development, a variety of approaches have been used by the research community and practitioners in industry. A need was felt for a comprehensive, coherent source of knowledge in this field on which to base the case studies, and also as a means to providing a single source of information to users of this resource. Accordingly, a literature review was conducted and an overall process description was developed. This paper presents and describes the online learning resource which was developed. In addition, the literature review and the process description of platform planning that were developed are also detailed. Product platform planning, online learning tool, case studies.