Abstract: A design structure embodied in a machine readable storage medium for designing, manufacturing, and/or testing a system chassis includes multiple chassis bays configured for receiving either of a single, conventional server blade or an adapter blade is provided. The adapter blade can selectively secure a plurality of compact blades, such as a blade PC. The adapter blade includes an interposer disposed for electronically communicating each compact blade with a server interface as a separate node upon securing a compact blade within any of the adapter bays. Each compact blade may be configured as a server, a “client blade” or “blade PC”, or a companion blade providing application-specific features. Therefore, the use of an adapter blade increases the flexibility of and capability of the processor system.