Antarctic sea ice has usually been able to recover in winter. But this time it's different, with levels taking a sharp downward turn at a time of year when sea ice usually forms reliably — and experts are worried.
If you read the section on etymology of the business term, it was referring to the metric of quality control. Basically it means your QC is so good that a bad unit gets shipped only a tiny fraction of the time.
Processes that operate with “six sigma quality” over the short term are assumed to produce long-term defect levels below 3.4 defects per million opportunities (DPMO). The 3.4 dpmo is based on a “shift” of ± 1.5 sigma explained by Mikel Harry.
If you read the section on etymology of the business term, it was referring to the metric of quality control. Basically it means your QC is so good that a bad unit gets shipped only a tiny fraction of the time.