Just last week, we posted the story of Boeing’s intended takeover of its troubled fuselage provider, Spirit AeroSystems. Today’s post is a story of quality control at Boeing. You will recall that a door blew off an Alaska Airlines flight in January because a few bolts were not properly installed. Months before the 737 piece blew out midflight, the plane spent nearly three weeks shuffling down an assembly line with faulty rivets.
In turns out that workers had spotted the bad parts almost immediately after the plane’s fuselage arrived at the factory from Spirit, reports The Wall Street Journal (March 12, 2024) . But they didn’t make the fix right away and the 737 continued on to the next workstation. (See the Chapter 9 photo on page 383 illustrating the assembly line process). When crews completed the repair 19 days later, they failed to replace four critical bolts on a plug door they had opened to do the job, leading to the accident.
At Boeing, there is a term for situations when work is completed out of the production line’s ordinary sequence: traveled work. This practice of completing work out of sequence is a liability when it comes to airplane quality. “The folks on the line, they know what it is,” Boeing CEO said. “It creates opportunities for failure.” Yet, four years ago, Boeing laid out 5 values central to improving safety. Number 3 on the list: eliminate traveled work.
Doing work out of order complicates the intricate, taxing process of putting together an airplane. In the 737 factory, each plane moves its way through a series of stations, where crews are tasked with completing certain tasks. Those stations are equipped with tooling, platforms and crews trained to do the jobs designated for the site. Planes advance to the next station every 24 hours. Keeping production lines moving even when certain parts aren’t available for a given job helps avoid costly slowdowns.
When a missing part prevents workers from finishing, the plane still moves ahead and the part gets added or repair is completed somewhere down the line. Sometimes, the work isn’t done until the plane leaves the factory. But the proper tooling may not be on hand there, leaving workers moving back and forth to get the necessary equipment.
Classroom discussion questions:
- As the new OM head of the 737 line, what is your recommendation?
- Can an assembly line like this be stopped?