A central part of basic engineering design education aims for imparting profound knowledge of how machine elements are designed and building an understanding about how they work in detail within a technical product. In this context, a basic challenge lies in teaching to analyse complex systems that are usually characterized by a high number of interacting parts and interfering movements. In our basic engineering design education at (blended for review), we recognized that high-performing students in functional analysis are able to gain more insights from analysing machine systems than low-performing students. Indeed, high-performers are not only effectively using previous knowledge, they are also more successful in identifying relevant parts. This observation raises two questions. (Q1) Which previous knowledge is required to single-handedly be able to fully understand how a specific system works? and (Q2) How can we support students in drawing special attention to the relevant parts and the areas revealing their role within the system? In order to answer these questions, we conduct a mobile eye tracking study, including concurrent reporting. Students are asked to analyse a small, but difficult to understand machine system and to explain how it works. This paper highlights the differences between successful und and non-successful functional analysis and discusses them in the context of the two questions presented above. The two main results of this paper are that successful students had a wider knowledge-base of mechanical systems and that analysis strategies like “following the flow line of force” gives a guide rail. Both helped them to identify single subfunctions and to evaluate their importance
