A Basic Understanding of Six Sigma Repeatability and Other Terms

The knowledge of Six Sigma repeatability and reproducibility along with other processes are invaluable to company executives looking to improve the quality of their company. Typically, a person called a Six Sigma Champion will present the executives with a detailed description of the services the professionals will provide when analyzing the company’s current processes to find flaws and areas that need improvement. These Six Sigma professionals will sort through all the details and will consult with the company executives when important decisions need to be made.

Trained and certified professionals within the Six Sigma Methodology work on a system of belt colors. The colors represent how experienced and knowledgeable the professional is. The leader of the project is the Black Belt. The Master Black Belt will consult with the rest of the team, if necessary and is responsible for training all of the other belt levels within the Methodology. The project leader or Black Belt, will gather the proper information, construct the project, and choose team members from the employees that will suit the needs of the particular project they are working on.

A Black Belt is usually assisted in the project by a Green Belt professional. The Green Belt works between the lower and upper level professionals. The Yellow Belt professionals work as the support system for the project. They also work with White Belt representatives, who only work on a local basis, helping the project connect with local resources.  Yellow Belt professionals are the employees and staff of the company, searching for flaws and faults within the daily procedures that need to be altered. They will develop possible solutions and work with the Green and Black Belt professionals to sort through and expand on the best options.

The reproducibility and repeatability processes are used in measurement system analysis. The company uses this type of analysis to pinpoint measurements within the company. These measurements have variations that can sometimes cause fluctuations and errors. When the variations and errors must be measured within an analysis, the Six Sigma professionals repeat and reproduce the analysis for accuracy.

Professionals in Six Sigma use flowcharts and graphs to assist in analyzing the company processes and procedures that are currently in place. They search for any faults or flaws that could be causing obstacles and delays in daily functions. Fishbone diagrams and histograms are used to help the team explain the results of the project and the possible solutions. The streamlining and lean processes used by these professionals help the company eliminate unnecessary costs and make a higher profit.

The variations that are often found in measurement systems can cause outcomes to be varied or not quite accurate. Since accuracy is vital to the success of a business, these measurements must be double checked. The processes must be controlled to eliminate a chance of variations causing inaccurate outcomes. Different measurement tables and different people are used to repeat and reproduce measurement analysis reports. This helps to break up any monotony and make the measurements more consistent with the desired outcome.

Six Sigma repeatability and reproducibility are used in gage R&R studies. This is a process by which the measurement systems are checked for accuracy. There are many procedures used by the Six Sigma team along with these to assist the company in recognizing flaws in the system and developing solutions to stabilize a company so that they have the best chance possible for success.


Originally developed by Bill Smith at Motorola in 1986, the Six Sigma Training program was created using some of the most innovative quality improvement methods from the preceding six decades. The term "Six Sigma" is derived from a field of statistics known as process capability. The term 6 Sigma refers to the ability of manufacturing processes to produce a very high proportion of output within specification. Processes that operate with "six sigma quality" over the short term are assumed to produce long-term defect levels below 3.4 defects per million opportunities. Six Sigma's goal is to improve overall processes to that level of quality or better.