Part 1 of this series dealt with overall wiring system design as providing the critical foundation for the growth in automotive electronics systems and functionality. In that installment we looked at how to develop a set of system diagrams into a specific vehicle architecture, taking into account the complexity of a modern vehicle (both in terms of components and the option/variant complexity arriving from increased customer choice).
Part 2 looked at simulation and analysis techniques that can be applied to an electrical distribution design flow to make it more efficient and less costly.
Building automotive electronics wiring harnesses is a tough businessonly the fittest suppliers survive. Harness makers are challenged with delivering products that are increasingly complexand with improved quality at a lower price tag. Standing still is not an option, as competitors are constantly battling to snatch market share.
To remain competitive and preserve margins, harness makers are forced to continually innovate in all areas of their business. This installment looks at some key design process issues facing automotive harness makers and assesses the impact of these concerns. Part 4 will go on to describe how new software tools are helping harness providers solve some of these critical problems.
Design flow issues and impact
The high-level flow shown below describes the inputs into the harness design process, which is normally undertaken by the harness supplier.
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Four types of input data (at left of diagram) are merged within a harness design software application:
Wiring data, which originates from the vehicle electrical design
Physical harness information (branch geometry, coverings, clips, etc), which originates from the mechanical design domain
Configuration data that describes option relationships and, hence, describes variable content within the harness
Component data, originating from a library of approved components
These inputs are brought together electronically, and the design is then enriched and validated using a combination of manual and automated processes. Examples of design enrichment include component selection and adjustments to facilitate low cost manufacturing.
Once the design is complete, a set of outputs is produced (at right of diagram above), such as harness prints, cost analyses, and data feeds to downstream processes (ERP systems, for example). Of course many facets of this process can be scrutinized and areas for improvement identified.