Six Sigma is a methodology comprising various techniques and tools aimed at improving processes. Introduced by Motorola in 1986, Six Sigma focuses on enhancing the quality of process outputs by identifying and eliminating the causes of defects (or errors) and minimizing variability in manufacturing and business processes. It employs a set of quality management techniques, including statistical methods, and builds a specialized framework within organizations with roles such as "Champions," "Black Belts," "Green Belts," and "Yellow Belts," who are experts in Six Sigma. Each project within the organization follows a structured approach, with clear objectives such as reducing process cycle time, minimizing pollution, lowering costs, improving customer satisfaction, and boosting profits. These are also core to the principles of Total Quality Management (TQM), as highlighted by Peter Drucker and Tom Peters, especially in his book In Search of Excellence, which references Motorola's Six Sigma principles.
The term "Six Sigma" comes from manufacturing terminology, particularly statistical modeling of manufacturing processes. The maturity of a process is measured using a sigma rating, which indicates its yield or the percentage of defect-free products it produces. A Six Sigma process is one in which 99.99966% of all outputs are expected to be defect-free, corresponding to 3.4 defects per million parts. However, in practical terms, this corresponds to a 4.5 sigma level. Motorola set a goal of achieving "six sigma" in all its manufacturing operations, and this term has since become synonymous with the management and engineering practices needed to meet that goal.
Benefits of Six Sigma
Organizations that implement Six Sigma effectively see a range of significant benefits that provide a competitive edge and help shift the culture from reactive problem-solving to proactive prevention. Proven advantages include:
For the Organization:
- Significant cost savings, typically 5% to 20% of annual turnover
- Improved product or service quality, as perceived by both internal and external customers
- Shortened process cycle times
- Enhanced employee skill development
- A common language for problem-solving throughout the organization
- Achievement of world-class operational standards
For the Individual:
- Expanded knowledge and expertise
- Ability to apply a variety of problem-solving tools and techniques
- Global recognition and professional status associated with Six Sigma expertise