Abstract Just as we transitioned from simplistic lead frames to large ball grid arrays decades ago, we find ourselves again at another inflection point in design. Originally a derivative of PCB design, IC package design finds itself straddling both PCB-style design and traditional IC design. Dimensions have shrunk to place IC package design squarely in the same design dimensions as integrated circuits. Likewise, with Moore's law rapidly losing steam to support SoC's as a system integration vehicle, advanced package technologies have been asked to fill the system enablement gap. We now see advanced packaging technologies with silicon content as the system enabler in 2.5D, 3D and fanout wafer-level packaging. Because of the silicon and small geometries, IC design flows and signoff mechanisms are being used to design the next-generation of packaged systems. Package design now finds itself in the forefront of system-level design enablement. Where once system aggregation was done in a SoC at the silicon level, packaging is being used to build a system from technology-optimized die from each functional area (memory, processing, and interfaces). Silicon is no longer just a substrate material for IC manufacturing but a “package” substrate and functional integration vehicle. As such, package design teams find themselves adding IC-based design flows and methodologies. Package designers must look to the IC tools for routing, DRC, and signoff capabilities. Designers are looking for next-generation EDA tools to support these new integration and design challenges, including LVS-like validation checks and IC-based design rules. Rather than transitioning the design team from traditional packaging tools to IC tools entirely, we propose that users can leverage complete design flows that merge the best-in-class capabilities from each of their respective design domains. Is this regard, the best-in-class capabilities can remain in their respective domains, and a design flow can be created that relies on tight integration between both domains. These flows can also leverage a single point of entry for design capture and system level management. Flows based on the system management tool and the appropriate features in each of the domains can be created that enable and optimize complex designs that meet physical, signal integrity, cost and performance requirements. We will describe how capabilities can be leveraged from both domains in a tightly coupled flow, overseen by a design system-management tool, to address the challenges of advanced-technology and silicon-based system.