Once the electrical components from the system schematics are placed and the signals routed and wires synthesized, it’s easy to visually indicate the various metrics the engineer chose for evaluation. Charts and graphs are helpful in understanding the effects of the constraint results.
The screen in Figure 4
depicts two different harness architectures. They vary as to whether the aircraft has a single aft equipment rack or whether there are two equipment racks; one located on each side of the fuselage. This example contrasts weight differences between the two equipment rack possibilities. It shows that one of the architectures saves weight on the rear fuse harness. The engineer can easily evaluate various alternatives and quickly converge on the one that provides the most value to the stated business and product objectives.
Figure 4: Evaluating different harness architectures.
In addition, the engineer can retrieve information such as bundle diameters, parts count, etc. This data can be electronically shared with MCAD engineers to help them understand access-hole requirements and get an early look at clamp provisions, and so forth. What was once considered late-cycle information is now at the designers’ fingertips much earlier in the design process.
Systems integration decisions such as grounding and terminal module definition, shield termination specification, etc. are easier to make with a platform-level view; the result of the wire synthesis is a complete first-pass wiring definition of the platform.
Physical wiring views
Tools used in this way can then automatically generate diagrams of the wiring implementation based on the perspective of the engineer’s partition. For example, diagrams are often partitioned per subsystem. Because the wiring data is in a database, it’s easy to query for specific data and to generate a graphical view. Control of the layout, directionality, and aesthetics can be automated via styling templates. Instead of the wire diagram being a manually created document that is susceptible to data re-entry errors, it becomes an automated output of the platform’s wiring definition. The engineer can easily regenerate the document if the model data changes. The time spent manually creating wiring diagrams is greatly reduced.
Production planning needs access to current and accurate engineering data. In the platform-level engineering flow, all operations are done with tools tightly integrated in a database, and the internal data structures are represented as they are in real life. The database contains the information, for instance, that a given connector has specific-sized cavities in which particular contacts can be inserted. The database also contains the information on the relationships that contacts have with the wire sizes they can accept. Harness planning and associated manufacturing process modeling becomes a much more streamlined activity.