Six Sigma

What is 'Six Sigma'

Six Sigma is a quality-control program developed in 1986 by Motorola that emphasizes cycle-time improvement and the reduction of manufacturing defects to a level of no more than 3.4 per million. As of 2016, Six Sigma has evolved into a more general business-management philosophy focused on meeting customer requirements, improving customer retention, and improving and sustaining business products and services. Six Sigma is applicable to all industries, and a number of vendors, including Motorola itself, offer Six Sigma training; special certifications include yellow belt, green belt and black belt.

BREAKING DOWN 'Six Sigma'

Six Sigma represents an ideology that focuses on statistical improvements to a business process. Six Sigma advocates for qualitative measurements of success over qualitative markers. Therefore, practitioners of Six Sigma are those business people who use statistics, financial analysis and project management to achieve improved business functionality.

Six Sigma has evolved to define numerous ideas within business and is sometimes confusing. First, it's a statistical benchmark. Any business process that produces less than 3.4 defects per 1 million chances is considered efficient; defects are considered anything that's produced outside of consumer satisfaction. Second, it's a training program and certification that teaches the core principles of Six Sigma. Practitioners can achieve Six Sigma belt levels, ranging from white belt to black belt. Finally, it's a philosophy that promotes the idea that all business processes can be measured and optimized.

The Five Steps of Six Sigma

True believers and practitioners in the Six Sigma method follow an approach called DMAIC: define, measure, analyze, improve and control. It is a statistically driven methodology that users learn through Six Sigma certification or companies implement as a mental framework for business process improvement.

The ideology behind DMAIC is that a business can solve any seemingly unsolvable problem. First, a team of people, led by a Six Sigma champion, defines a faulty process on which to focus, decided through an analysis of company goals and requirements. This definition outlines the problem, goals and deliverables for the project. Second, the team measures the initial performance of the process. These statistical measures make up a list of potential inputs that may be causing the problem and help the team understand the process's benchmark performance.

Third, the team analyzes the process by isolating each input, or potential reason for failure, and testing it as the root of the problem. Through analysis, the team identifies the reason for process error. From there, the team works to improve system performance. Finally, the team adds controls to the process to ensure that it doesn't regress and become ineffective once again.