From the International Quality Federation, USA
Six Sigma is a highly disciplined process that helps us focus on developing and delivering near-perfect products and services.
Black Belts are at the core of the Six Sigma implementation. ‘Black Belt’ is an individual who has developed a synergistic proficiency between his or her technical discipline and the Six Sigma strategies, methodology and tools. Black Belt skills are not only required for people working in Quality department as they improve the productivity of people in all other functional departments also.
The major role of the Six Sigma Black Belt is overseeing teams of Green Belts, who are responsible for most of the actual Six Sigma work within the hierarchy. For a Six Sigma student to earn a Black Belt, they must master the Green Belt curriculum as well as show that they have a clear understanding of the more advanced concepts of the Six Sigma methodology. Six Sigma students aspiring to become Black Belts must also show that they clearly understand the lean enterprise theory and must also show their understanding of the DMAIC paradigm.
Six Sigma Black Belts have the responsibility of overseeing Green Belts, and who can move up to Master Black Belt and beyond from this position. Black Belts will double-check the work of the Green Belts, and may even be able to improve on the overall work of the Green Belts.