The Public Switched Telephone Network - The public switched telephone network (PSTN) is the international network of circuit-switched telephones. Learn more about PSTN at HowStuffWorks. x
Black Belt Certification. The IASSC Certified Lean Six Sigma Black Belt (ICBB) is a professional who is well versed in the Lean Six Sigma Methodology, who leads improvement projects, typically in a full-time role. A Lean Six Sigma Black Belt possesses a thorough understanding of all aspects within the phases of D-M-A-I-C.
Six Sigmaâs Belt System Provides Structure. You may have heard that Six Sigma makes expert use of statistical measurement and quantitative analysis, and while this is true, Six Sigmaâs greatest strength may be the way it organizes people. Six Sigmaâs greatest asset in coordinating and managing the people who employ it may just be its belt system. The belt system is composed of a ranking system similar to the hierarchy in some martial arts disciplines. The belt system helps establish a chain of command among employees with Six Sigma training.