In the recent years, a shift from document-based to model-based approaches is going on within many organizations and industries involved in the development of complex systems. Model Based Systems Engineering (MBSE) methods and tools are in fact gaining more and more popularity due to all their claimed benefits over traditional document-based approaches, including for instance enhanced design quality of systems, clearer development of system requirements and specifications and improved communications within the design teams. However, these benefits can be possible only if recommendations on how generating and representing design information during the development process are made available. The present paper introduces a new model-based architectural framework, i.e. a guideline that leverages a modeling approach for the development and representation of complex systems. More specifically, the MBSE architectural framework addressed in this paper focuses on the system architecting activities of a Systems Engineering Product Development process, i.e. when multiple conventional and innovative solutions of the systems are generated to address all the system stakeholder expectations. The proposed architectural framework aims at fostering the agility of the development of complex systems, in order to streamline, improve and accelerate their architectures definition and modeling through an MBSE approach. The paper provides details of the MBSE architectural framework, including the means to produce and represent all the system development information. 10.2514/6.2022-3720