This paper discusses ways that model-based development lays the groundwork for an integrated design flow that addresses the complexity challenge once and for all. Thanks to recent advances in modeling languages and automation, model-based development can now be extended across the hierarchical levels of system design. System integration no longer needs to wait until physical subsystems are ready. At each level of design, models provide the ability to verify the design much earlier than waiting for actual HW/SW implementation. Integrating model-based development methodologies into the platform development life cycle has the potential to significantly reduce risks to schedule, cost and quality for system integrators. With the astute application of a model-based development approach, the 11th hour is no longer a threatening milestone in the life cycle of a development program.