With regards to methods of assembly systems planning we are familiar with the depiction of the technical structure using capacity fields and graphs in addition to the modelling of assembly activities as a precedence diagram. However, no form of presentation has yet been defined that describes the assignment of staff within an assembly system. This paper discusses the concept of the staff assignment graph used to balance a hybrid assembly system, and in doing so marks a first attempt to close this gap and develop a more comprehensive planning method. The paper also explains how to evaluate staff assignment graphs and presents an algorithm for automatically generating them based on existing capacity graphs and taking a multi-criteria goal function into account.