In this paper an extension of the design method graph-based design languages is proposed. This is realized by adding object-oriented class methods and interface mechanisms to the design method. Additionally, graphical mechanisms for modeling and calling the methods are proposed. This allows object-oriented design patterns to be transferred to the product design, where they improve the handling of complexity in the product engineering. As result, the proposed extension enables modularization and reuse of engineering knowledge, the integration of engineering domains is enhanced and multi-stakeholder collaboration with security access control (information security) becomes feasible.