A rapidly growing approach in product design and manufacture, with great potential to improve customer value, is mass customization. The possibility to design and manufacture highly customer adapted products brings a competitive edge to manufacturing companies and is in some areas a necessity for doing business. In this paper, an approach for documentation and knowledge management of systems supporting the design and manufacture of customized products is explored. As the governing framework and models are updated and refined due to shifting prerequisite, the system and hence the solutions generated for a single specification will change over time. This affects product management and the ability to meet legislation and customers' requirements regarding documentation and traceability, as well as the company's ability to provide services, maintenance and supply spare parts. A solution has been developed for an industrial case with required functionality for capturing, structuring, searching, retrieving, viewing, and editing a system's embedded information and knowledge. The objective is to enable and facilitate system maintenance and updating and support the reuse of functions and system encapsulated generic design descriptions in future systems.