According to a study performed by the Project Management Institute, around 47% of unsuccessful projects do not meet their goals and objectives due to poor requirements management. Taking requirements into account during the aircraft design process and ensuring requirement compliance during all design phases is important to obtain good and feasible aircraft designs. However, a typical aircraft design process is very complex and many requirements need to be taken into account. This paper proposes a new framework that implements requirements in the design process by establishing a direct link between Model-Based Systems Engineering and Multidisciplinary Design Analysis and Optimization (MDAO). Model-based requirements are directly implemented in the optimization problem and based on the requirement verification methods the MDAO workflows are formulated. When requirements or verification methods change, the workflow is automatically updated accordingly. This way, requirement compliance can either be automatically enforced or checked based on the optimization or analysis results. Automatically generated requirement reports provide information on the requirement compliance results. The framework has been implemented in a software prototype, which was applied to the design of a wing box, showing the functionalities of the framework. With the framework, the traceability from requirements to product design is improved, as all stakeholders can see how the design process was formulated and how requirement compliance has been achieved. Furthermore, optimized designs can be obtained that satisfy all the stakeholders' needs.