Once again, Tesla demonstrates no understanding of volume manufacturing! Newspaper: “Tesla reworks 40% of its parts.” Tesla response: “But we inspect every car carefully before shipping it!”
Tesla fires back against a CNBC report that cited unnamed employees’ complaints about the electric carmaker cranking out a high number of parts that need to be repaired or replaced. Tesla say…
But as Deming and others pointed out decades ago, you cannot achieve good final quality by doing lots of inspection. There are many reasons for this, including that inspection/testing is not 100% accurate. The whole field of statistical process control, which eventually morphed into today’s “Six Sigma,” was invented as an alternative to massive inspection.
So if Tesla claims that it can make parts so poorly that 40% need rework, but still have defect-free cars, it is an admission of ignorance. This continues Tesla/Musk’s consistent pattern of not understanding that high volume manufacturing is not just “low volume manufacturing repeated many times.” (See my October post about Tesla’s attempts to ramp up Model 3 production.)
My suggestion for people with a Model 3 on order: don’t expect it to be on time, or have good build quality. Sorry.