Control Chart Types - How do I Choose the Right One?
What's the difference between variable and attribute control charts?
If you are struggling with these questions, you are not alone.
You can take classes, read articles or find a good decision tree, but next week, you won't remember what you learned...
That is why we built control chart selection rules right into the code of QI Macros add-in for Excel. Here is what you need to know.
There are two main categories of control charts:
- Variable control charts for measured data (most often decimals, e.g., 3.24).
- Attribute control charts for counted data (most often integers, e.g., 1, 2, 3).
Within these two categories there are seven standard types of control charts. These are often refered to as Shewhart control charts because they were invented by Walter A. Shewhart who worked for Bell Labs in the 1920s.
QI Macros can analyze your data and choose the correct Shewhart control chart for you
Use for Measured Data
time, money, length, width, depth, weight, etc.
Often contains decimals (.006, 8.9, 74.05)
Use for Counted Data
number of defects, errors or defective items
Always a whole number (1, 44, 75)
Why are there so many types of control charts? What makes them different?
Each control chart uses a different formula to account for three characteristics of the underlying data:
- The type of data (measured or counted)
- How measurements are grouped or what is counted
- The sample size
It sounds scary, but its not because...
QI Macros Add-in for Excel:
Installs a new tab on your Excel menu. You dont't need to learn a new application.
Will make the calculations for you. You don't need to learn any formulas.
Will analyze your data and select the right chart for you. You don't need to memorize rules or get lost in a forest of decision trees.
It is so simple to use and anybody can use it. It's like a magic program.
You input the data, you click the button and, "poof," there it is!
It's all done for you. It's great, I love it...
- National Association of Healthcare Quality Conference
QI Macros Draws These Specialized Control Charts Too
- Watch Control Chart Wizard Video
- Control Chart Limits
- Control Chart Decision Tree to Choose the Right Control Chart
More Reasons to Choose QI Macros
- Only $329 USD - less with quantity discounts
- No annual subscription fees
- Free technical support
Easy to Use
- Works right in Excel
- Create a chart in seconds
- Easy to customize & share charts
Proven and Trusted
- More than 100,000 users
- In More than 80 countries
- Five Star CNET Rating - Virus free