|
Contents
| Quality Encyclopedia
| Discussion Blogs
X-BAR
& SIGMA CHARTS
X-bar & Sigma Charts
are a set of control charts for variables data (data that is both quantitative
and continuous in measurement, such as a measured dimension or time). The
X-bar chart monitors the process location over time, based on the average
of a series of observations, called a subgroup. The Sigma chart monitors
the variation between observations in the subgroup over time.
See also:
SPC
Concepts
When
to Use an X-bar / S Chart
Interpreting
an X-bar / Sigma Chart
X
Bar Chart Calculations
Sigma
Chart Calculations
Our X-bar & Sigma Chart
accurately accounts for subgroups of varying sizes using Burr weighting
factors to determine process sigma (Burr,1969). For a general discussion
of X-bar / S Charts, refer to any Statistical Quality Control textbook,
such as (Pyzdek, 1990, 1992a) or (Montgomery, 1991).
|
