ECAD is used to capture circuitry on systems level. Schematic sheets represent cable harness to give a FROM/TO for each wire to be routed in 3D. Schematic documents are signed-off by electrical engineering giving approval to route harness in 3D. A wirelist file is extracted from ECAD and imported into MCAD (3D CAD).
3D harness is routed with conductivity from ECAD giving true bundle diameters. Prototyping harness in 3D prior to build gives weight (mass) and center of gravity. Interference checks can be made to assure proper fit. Voltage drops are calculated based on wire lengths derived from 3D CAD and software simulation analysis. Wire splices are used to manage power distribution thus assuring enough copper to carry the current.
A flattened (stick) harness drawing is created from 3D providing a manufacturing document which shows takeout dimensions for each bundle. Connector reference designators correspond with those assigned in ECAD. A wirelist is on the drawing giving a FROM/TO for each connector pin with wire signal name, wire gauge and wire color.