Six-Sigma Program

The six-sigma program is a business improvement program that focuses on processes, variation reduction, and delivery of quantitative financial results. Six-sigma operates project by project with rigorous documentation of financial results. Other goals of the six-sigma program are to increase customer satisfaction and overall quality.

Six-sigma uses a measurement scale of process variation based on the normal distribution called the sigma scale. The higher the sigma, the fewer defects produced by the process. A process operates at a six-sigma level if it produces no more than 3.4 defects per million opportunities for defects. A three-sigma process produces 66,810 defects per million opportunities, a four-sigma process 6,210, and a five-sigma process produces 233.

Six-sigma programs require quality leaders or champions. These are high-level managers who develop the implementation plan, set objectives, allocate resources, and monitor progress. The other important members of six-sigma programs are the black belts. These are individuals with high leadership potential who have received training in statistics and other process improvement tools. This training typically takes six weeks. The black belts work full-time leading teams that work on the six-sigma projects. These projects typically take three months to complete and have definite financial targets. At General Electric (GE) the typical target has been $175,000. At GE most project teams have a member from the finance department who documents the financial impact of the project. The black belt position is intended to be temporary—typically two years. At GE a typical black belt completes 8 to 12 projects for a net savings of about $1 million. Being a black belt is intended to be a step to promotions. One of the goals of six-sigma is to develop managers with a continuous improvement mind-set.

Other positions in six-sigma programs are the green belts. These people have received more limited training and do not work full-time on six-sigma projects. There are also the master black belts. These are black belts who have advanced training in statistics and other quality improvement tools. They are responsible for all six-sigma work done in a particular area or function. Theirs is a more managerial function than that of the black belts. They select, train, and mentor the black belts. They help on project selection or approval, training, and review of projects completed. It is common for them to have weekly hourlong meetings with the black belts whom they are mentoring. Their position is full-time.

Six-sigma projects use the DMAIC methodology. DMAIC stands for five project stages: define, measure, analyze, improve, and control. In the define stage, the right problem is selected. In the measure stage, the cost of the problem is quantified. In the analyze stage, the causes of the problem are found. In the improve stage, the problem is fixed. And in the control stage, measures are put in place so that the problem does not recur.

It is claimed by some that the great impact of six-sigma programs is due to the creation of full-time positions for improving critical business processes.