we propose a new theory of Extended Affix Grammar derivations. The key idea is to use a graph grammar for modelling the two-level derivation process. This allows us to give a precise definition of a parse, which applies correctly to any well-formed Extended Affix Grammar. The concept of multi-pass parsing originates from practical compiler design, where parses are organized as a sequence of passes in order to avoid random access to the full parse tree. We demonstrate how this concept can be incorporated into our theoretical framework by means of canonical graph derivations. This allows us not only to establish the adequacy of the multi-pass approach, but can also be used as a complexity measure for Extended Affix Grammars.