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 and Green Belts are leading high-impact project teams focused on improving performance in areas of our business that are critical to customers. Six Sigma is making an impact on two levels. Provide the best care to patients and driving efficiencies in the business. Six Sigma projects are an integral part of the Operating Plans of every business unit in Quest Diagnostics.