"Cable Design Reuse Across Diagram Type Boundaries"
by Rick Cook and Rik Vigeland, Mentor Graphics Corporation

Cables designs are common among Automotive and Aerospace industries.
A fundamental object in the creation of a cable design is the harness.
The harness is generally a design consisting of wires connectors and
small components.  Large system-level designs consist of multiple
harnesses and LRUs (Line Replacement Units), but there are typically
additional designs or diagram types which are required.

Schematic designs, which are precursors to cable designs, are used
to show the electrical connectivity between LRUs, but may omit the
connector couplings which occur as signals pass through bulkheads or
various compartments.  Harness diagrams are used to manufacture a
specific harness type, which may be used (instantiated) multiple
times in the system-level design known as a System Wiring diagram. 
Signal Trace diagrams are created in order to follow connectivity
through the many sheets of subdiagrams or interfaces and to provide
technicians with diagnostic data.

In order to ensure that designers need enter data only once, and to
facilitate the extraction and transfer of that data bidirectionally
between diagram types, a methodology of design transfer was created.
This methodology supports both the creation of new designs as well as
a mechanism to compare existing source and destination designs in order
to perform incremental updates to the destination design.  Both
interactive and fully automated tasks have been made available through
form-based user interfaces, allowing users to perform diagram transfers
and instantiations, as well as helping drive what inevitably becomes the
designer's most aesthetic task: graphical layout of the cable design.

Fundamental best practices used in both the current methodology and
planned enhancements include correct-by-construction techniques,
design reuse, automated verification, and a central database.