Contemporary systems engineering developments are frequently global in scope, and 'distributed' in both graphical and temporal senses, involving many different design and analysis tools, across systems engineering and various specialist engineering disciplines. Currently there is little interoperability between these suites of tools. This situation can have real stagnating effects on systems engineering activities, and considerable detrimental economic, productivity and quality consequences. Neutral data exchange is one solution to this problem. The AP-233 systems engineering data interoperability standard will be a fundamentally important standard, making global systems engineering in heterogeneous design environments possible. The aims, approach and results to date of the SEDRES-2 project are described, and the most recent AP-233 data model is outlined. The modularisation process in the STEP community, and the relationship to other areas of work, is described. A mature semantic-level systems engineering interoperability standard is an essential enabler and a significant invigorator to distributed systems engineering.