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.
Black Belts Should Create Balanced Project Portfolios. The Six Sigma project matrix helps create a project portfolio that has both substance and merit. By partitioning projects into the four quadrants of the matrix, Black Belts will select tasks that please customers and improve the firm's bottom line.