The development of large-scale mechanical systems involves interactive negotiations among nontechnical and technical design stakeholders. Usually, two types of negotiations exist: (i) those between the nontechnical stakeholders and technical stakeholders with responsibilities for the overall system, such as chief system design engineers and project managers; and (ii) those within the design engineering groups who are responsible for design tasks at different system hierarchical levels, i.e., system, subsystem, and component. This paper addresses the interactive negotiations among the design engineering groups. A direct synthesis (DS) method was developed to support the negotiations by combining adaptive and interactive modeling system based surrogate modeling with a set-based “zoom-in” approach. A vehicle frontal structural system design example is used to demonstrate how to apply the DS method in industrial practice. The preliminary results show that DS has the potential to support the fast synthesis of robust design alternatives that satisfy performance requirements at the system, subsystem, and component level.