The platform-based design methodology [1] is based on the usage of formal modeling techniques, clearly defined abstraction levels and the separation of concerns to enable an effective design process. The METROPOLIS framework embodies the platform-based design methodology and has been applied to a number of case studies across multiple domains. Based on these experiences, we have identified three key features that need to be enhanced: heterogeneous IP import, orthogonalization of performance from behavior, and design space exploration. The next generation METRO II framework incorporates these advanced features. The main concepts underlying METRO II are described in this paper and illustrated with a small example.