Six Sigma originally developed from engineering principles of project processes and contains many statistical concepts which can empirically define, analyze, and quantitatively enhance these modes of project development. Much of what an individual learns while taking these training courses online or through their organization relates to statistics and the various terms used in this graphical methodology.

With statistics, a company can credibly predict potential problems or potential successes and gear their processes towards or away from a specific feasible development. Statistical concepts are not difficult to learn, but simply require a basic knowledge of mathematical principles and the idea of certain variability within any process.

Degrees of Freedom

In statistics, degrees of freedom are the amount of independent data values utilized when guessing the value of a population parameter. This number is always going to be "n - 1" in any standard deviation because without subtracting the "1", the values would return as biased. In other words, degrees of freedom can be thought of as a necessary restriction in order to calculate a statistical estimate from another statistical estimate. In Six Sigma, degrees of freedom are used when estimating potential defect amounts in a product process from beginning to end.

Central Limit Theorem

Emerging from the theory of probability, the Central Limit Theorem asserts that the sum of self-regulating observations arising from the same distribution will contain a normal distribution. In addition, CLT states that as the amount of observations enlarges, this estimation will progressively improve. Using CLT in Six Sigma is helpful because it can analyze and validate subgroup or sample means, regardless if the actual process is conforming to normal distribution. Products can therefore be tested employing the CLT during the process for preventative error control

Histograms

Six Sigma methodology frequently utilizes histograms to represent and analyze the distribution of values in a specific set of project data. Histograms are valuable because they provide summaries regarding the shape and symmetry of a distribution, which can convey important information to an organization about the successful marketing (or failure) of a product. By examining a histogram, a manager can readily see how much product is selling, when the most is being sold, or when sales are slow.

Six Sigma Statistical Software

When participating in an online black or green belt course, you will no doubt be introduced to Statistical software, which contains all of the various statistical tools necessary to the success of adhering to Six Sigma methodology within your company. After the appropriate data is entered, this software will calculate information such as standard deviations, sigma, means, X-bars and many other concepts.