In product development practice, it appears that engineering activities very often focus on the variation of the physical embodiment, as this is where the greatest and most obvious implications for the product seem to be perceived. Nevertheless, an empirical study revealed that variation in physical embodiment affects many other dimensions of a product, such as properties and functions. Within the scope of product specification, this requires a stronger differentiation of various dimensions of system elements. For this purpose, initial challenges and solution approaches in automotive product development practice are analyzed to gain a deeper understanding of the interrelationships of the variation of different types of system elements. The gathered findings and insights are then synthesized in a comprehensive systematic consisting of the structuring of elements of a new product generation or the reference system and an understanding of the set of elements in the Model of PGE – Product Generation Engineering. In summary, the differentiation of the variation types of the element types “property” and “function” is confirmed via the conducted case study. ... mehrFurther research should focus on supporting the product developer in identifying the alterations of the system elements by deriving the generic variation operator specifically onto the system elements of properties and functions of technical systems.