The systematic development and improvement of products is directly related to the quality and management of the involved knowledge. In general, this knowledge is neither organized into specific categories nor treated and represented systematically and consistently. The classification and management of knowledge in terms of two categories: context knowledge and domain knowledge, leads to a systematic and expressive representation of knowledge involved in the development, evolution, and exploitation of solutions (products or systems). The definition of the process concept as the application of a context on a domain allow model and manage process and micro processes in the life cycle of any type of solutions. Context and Domain concepts are extended to consider the specific contributions of each one in the processes of the life cycle of Products Lines.