We will discuss the historys of a control chart using minitab and you can apply to many
aspects of the work
You can use control charts to track process statistics over time and to detect the presence
of special causes.Minitab plots a process statistic, such as a subgroup mean, individual
weighted statistic, or number of defects, versus sample number or time.
Minitab draws the:
• Center line at the average of the statistic by default
• Upper control limit, 3σ above the center line by default
• Lower control limit, 3σ below the center line by default
Special causes result in variation that can be detected and controlled. Examples include
differences in supplier, shift, or day of the week. Common cause variation, on the other
hand, is inherent in the process. A process is in control when only common causes − not
special causes − affect the process output.
A process is in control when points fall within the bounds of the control limits, and the points
do not display any nonrandom patterns. Use the tests for special causes offered with
Minitab's control charts to detect nonrandom patterns in your data.
You can also perform a Box-Cox transformation on non-normal data.
When a process is in control, you can use control charts to estimate process parameters
needed to determine capability.
Minitab offers a variety of options for customizing your control charts:
• See Control Chart Options for options specific to control charts, such as using stages
and tests for special causes.
• See Control Chart Display Options for options that are available before graph creation, such
as subsetting your data and changing the control chart's title.
• See Graph Editing Overview for options that are available after graph creation, such
as changing font size and figure location.
Exsamples of Control chart
The following examples illustrate how to generate control charts with Minitab.
Choose an example below:
1. Box-Cox transformation
2. X-bar and R chart
3. X-bar and S chart
4. I-MR-R/S Chart
5. X-Bar Chart
6. R Chart
7. S chart
8. zone chart
9. I-MR chart
10. Z-MR chart
11. Individuals chart
12. moving range chart
13. P Chart
14. NP chart
15. C chart
16. U chart