are a result of the design of the product and production system and generally account for about 80 to 95 percent of the observed variation in the output of a production process.

Special cause variation

Explanation:

Special cause variation generally accounts for 80 to 95 percent of the observed variation in a production process.

Common cause variation is a result of management's design of the system.

Common causes of variation are a result of the design of the product and production system and generally account for about 80 to 95 percent of the observed variation in the output of a production process.

Common cause variation is inconstancy affected by anonymous factors happening in a regular but irregular arrangement of output throughout the average of the data. It is a measure of the process potential, or wherewith entirely the process can work when specific condition change withdrew.

Common cause variation is additionally described as within-group variation, random variation, noise, inherent variation, non-controllable variation.  Though variance is an obstacle, it is an essential part of a process—variance will ultimately edge in, and it is not much you can do about it.

because she sucked. : )

(but so does trump, don't @ me)