Abstract: A process (100) and library element (14) product by that process for use with a design tool (18) to incorporate a complex electronic system (CES) (10) into a printed circuit board (PCB) (12) under development. The CES (10) is complex by virtue of having a plurality of connectors (20). The process (100) integrates physical data, and optionally also functional and other data, about the CES (10) into the library element (14). The library element (14) then may be stored and used from a conventional library (16) in the manner already widely used in the art for less complex elements.