A Breakdown in Communication

A communications cable was manufactured by a custom cable and harness supply house, and due to use, the housing had been removed along with the heat shrink so as to expose the blue and white wires.  What was visible is that the white wire on this cable is exposed; what you could not see was a single strand from the white wire hovering dangerously close to the blue wire. As the system vibration frequency changed within operation modes, the close proximity of the blue and white wires would cause an intermittent fault.  The result of the fault, considered by itself, was not too severe: the system shut down.  The resulting system-wide damage was costly, however, due to the thermal stress of multiple shutdowns.  Additionally customer perception declined quickly.

The failure is in the design, rather than in the manufacturer. The cable specified a wire gauge too large for the connector, causing the close proximity of the blue and white wires. An off-the-shelf bulkhead connector was specified due to cost and availability, while a custom design with smaller gauge wires would have cost more initially, it would have saved service time, product life, and customer perception.  How could the team have chosen the correct connector up front? Manufacturing drawings, tied together with an electrical design review, could have brought this problem to light prior to deployment.  While the hardware cost for the correct connectors was $100, compared to $5.00 for the bulkhead connectors, the overall cost of using the bulkhead connectors exceeded $8,000 due to travel expenses, service engineer cost and the cost of the software development tool to detect the problem.  The frustration level of the customer was elevated enough to call off the installation of another system Blogger Labels: case study,Failures,Breakdown,Communication,system
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