Control Chart Types
Control Charts fall into two main types: variable and attribute.
Variable (i.e., measured)
Variable control charts use measured data (time, money, length, width, depth, weight, etc.).
When looking at data, variable measurements often have one or more decimal places (e.g., 74.05).
The most common type of variable control charts are X charts:
- XmR - Individuals and Moving Range Control Chart
- X bar R - Average and Range Control Chart
- X bar S - Average and Standard Deviation Control Chart
- X Median R - Median and Range Control Chart
- I-MR-R - Individuals, Moving Range (between) and Range (within)
Less common types of variable control charts include:
- ANOM - Analysis of Means Control Chart
- Cusum - Cumulative Sum Control Chart
- EWMA - Exponentially Weighted Moving Average Control Chart
- Levey Jennings Control Chart
- Moving Average Control Chart
Attribute (i.e., counted)
Attribute type control charts use counted data (number of defects, mistakes, errors, injuries, etc.)
When looking at data, attribute data is always an integer (e.g., 1, 3, 5).
Common attribute type control charts include:
- c Control Chart
- np Control Chart
- p Control Chart (fraction defective) and q control chart
- u Control Chart (number defective)
Other attribute control charts include:
- Watch video of creating a control chart in Excel using the QI Macros
- Control Charts in Excel
- How to use and interpret a control chart
- Control Chart examples
- How to Choose the Right Control Chart with a control chart decision tree