The Boeing saga drags on, and what no one will tell you about manufacturing quality

A recent CNN story about a former Boeing employee who refuses to fly on the Boeing 737 Max went viral, throwing fuel on the fire over quality issues at the company. For manufacturing professionals, missing bolts — although serious — are not especially surprising. It’s not widely understood, but it is true that even 100% human visual inspection of a specification or attribute will not even come close to achieving zero-defect production.

Part of the reason is because of the natural limitations in human inspection, but a major issue is that inspectors are subject to the same personal issues that degrade their performance as any other employee. Legal and illegal substance use and abuse, physical illness, mental health issues and physical disability can all play a part.

How a corporation deals with underperforming quality control personnel is another factor. Automation of inspection processes will help, but can sometimes introduce a new level of uncertainty in quality assurance processes. Perfection will always be elusive, but statistically, the accident rate for air travel is at historic lows.

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