Original Equipment Manufacturer’s development teams are tasked with creating detailed product designs with drawings for new products. Mechanical components and assemblies are designed in 3D computer aided design (CAD) modeling software.  Printed circuit board (PCB) assemblies are designed in schematic and board layout software. These designs include all the connectors, switches, sensors and circuit board assembly outlines which are shown virtually in the 3D software. The 3D software accurately allows individual part designs to be completed, and drawings to be released from the virtual system design without first making physical parts.

Guess what system is typically missing from this virtual mechanical 3D design?

It’s the electrical cables and wires that connect all the circuit boards, motors, switches, sensors, connectors, etc. Cable assemblies and wire harness routing design and drawings are typically completed at the physical prototyping phase. This can be months later when the first prototype mechanical parts and circuit boards are ready to assemble.

Why is this an issue?

  • Relegating electrical wiring design to the prototype phase leaves little room for error. There is no time to try or test anything new or addresses any surprises.
  • Any incorrect estimations in the design regarding wire harness assembly positioning or what components are needed, will force the electrical wiring to adapt to what space, routing, or connection components are available in the completed mechanical and circuit board design.
  • Drawings given to the supplier at the prototype phase tend to be rushed and often incomplete. At this stage, with the design and schedule locked-in, restricting the suppliers ability to react and respond with design improvements, may cause increase in costs and needless delay.
  • Communication with OEM is through buyers/planners (focused on price and schedule). The OEMs technical development team has moved on to debug and product introduction.
  • On medical equipment, more than 30% of all reported service repair costs over the life of equipment are attributable to the electrical wiring system.

Benefits of designing wire harnesses during the design phase.

  • Wiring development will no longer impact product development schedule.
  • The OEM mechanical team can see exactly where connectors, cable and wire routing, and fastening or cable management are needed. The appropriate space and features can be provided and documented.
  • There is ample time to try and test alternate components, designs, and update B.O.M’s. Alternative components can improve end price, flexibility, and lead times.
  • The OEM has time to get harness prototypes from cable and harness manufacturers, allowing manufacturer’s to provide DFM feedback.

Any questions regarding this article please contact Andy Dahl.

Andy Dahl - Business Development Director - 1-833-247-7951

a.dahl@tlcelectronics.com

References:

https://wiringharnessnews.com/article/why-dont-oems-involve-you-in-their-design/