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 Sigma Green Belt â Choosing Wise Projects and Teams. A Six Sigma Green Belt is a certification that employees or one person can earn through Six Sigma courses. This type of training offers you the knowledge to skillfully see how to make improvements throughout a company, and even methodologies on team building and leadership. As a Green Belt in Six Sigma you will have already taken prior Six Sigma Yellow Belt training, teaching you the basics.