Get the Facts!

Our new innovative product on the new 747-400 was experiencing a high failure rate during installation. Boeing engineering pointed the finger back to us as producing a failure prone product. However, due to our recent adoption of SPC tools and processes the failure modes were not indicative of a manufacturing related defect or failure.

Boeing was new to the SPC process and even though they were dictating that many of their suppliers adopt it they put aside our SPC evidence and remained firm in their belief with non-SPC data as their basis. We made repeated requests for Boeing engineering to go out onto the assembly line and talk to the installers to get a first hand understanding of we configuration in which the units were failing. These requests went nowhere and were denied. They were hesitant to do their own due diligence and have engineering talk the installers to get further details – a classic engineering/manufacturing silo effect.

Coincidentally British Aerospace was also putting our product, same design different package, on their new regional commuter jet the BAE 146. I made a courtesy visit to their factory and they greeted me with the news of our product “failing on the line”. I took the opportunity to ask if I could go into an aircraft where the product was installed and talk to the installation team. They immediately complied in an interest to get to the bottom of the problem.

While I did not have any detail failure analysis of these units I suspected that the failures they were having were of the same order as those at Boeing. I was escorted into a selected aircraft that was in the stage of assembly where our product was installed. I was introduced to the supervisor who quickly confirmed that the units were failing at a high rate. I asked to talk to the actual person who installed the units. He was nearby and said that yes, the units were failing but that was not the whole story. When the installed unit failed he would install a second unit and if it failed he then tested the wiring harness and almost in every instance he discovered a short in the wiring harness that was damaging our product. Our product was in fact testing their wiring harness to see if it was defective or not – an expensive proposition.

I asked if the wiring harnesses were high pot tested and they did not know. The engineering manager that I was with took me over to the wiring assembly area where the harnesses were assembled on large tables. The supervisor there said that at that time the harnesses were not high pot tested but they had a request into management to purchase the test adapters and equipment for the test but it had not been approved.

I returned to Seattle and immediately called for a meeting with Boeing where I presented my findings from my visit to British Aerospace. They were somewhat skeptical that what happened at BAE would occur at Boeing. I requested that they provide evidence that the 747-400 harnesses were high pot tested. A week late Boeing engineering reported that in fact the cause of the failures of our product was resolved. An immediate change had been made in their wiring harness process to high pot test them before they were put on the aircraft. Boeing accepted responsibility for all of the return units the “failed” and further failures dropped to a near zero level.

When failure modes don’t add up, trace the problem to its root cause and understand the failure environment. Go to the source and “get the facts” to make sure you are getting the real story. Too often organizational barriers filter information which is further distorted as it is passed through multiple people on its way to you and even within your company. It is amazing how quickly problems can be solved when you have the complete information.

Get the facts!


  1. […] SPC was used by a supplier to Boeing to identify that returned failures were not due to the original manufacturing process, but due to the absence of testing related parts produced at Boeing. See “Get the Facts.” […]

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