The 1.5 Sigma Shift

This is a topic that many Six Sigma practitioners put in lot of effort in their Six Sigma research.

Actually, there is no evident to prove most manufacturing process shift within 1.5 Sigma over a long term process.

Experience from Motorola shows that Sigma level of a long term process may be shift within the 1.5 sigma range due to uncontrollable external factors. Don’t forget, Motorola is a big organization that involves many complicated manufacturing processes. At which process the engineers encounter the shift and can 1.5 sigma level shift applicable to all processes under Motorola organization? This is still a big question mark.

I would say, 1.5 is just an artificial number for benchmarking. It is not necessary applicable to all, therefore, why bother so much about the magic number?

Last update : 27/03/08