Noblis is supporting the development of a NOAA-wide observing system architecture. The initial step is to create a roadmap that ensures a rational, traceable, and efficient allocation of user requirements. Our engineering knowledge of formal requirements definition and acquisition, our experience in applying this knowledge to solve our clients' problems, and our understanding of NOAA's organization and missions made Noblis the logical candidate for this effort. Working with NOAA, we have developed a process to identify, collect, standardize, prioritize, validate, consolidate, and update NOAA's environmental observing requirements. Noblis worked with the NWS to apply the NOAA model to its own needs, creating the NWS Operations and Services Improvement Process (OSIP).