X bar S Chart Excel
Use an X bar S Chart (Average and Stdev Chart) to Evaluate Stability of Processes Using Variable Data
Here is an example of an X and Standard Deviation chart created using the QI Macros for Excel.
The X bar S chart can help you evaluate the cycle time for almost any process: making a widget, answering a customer call, seating a customer, delivering a pizza, or servicing an appliance. This chart is especially useful when you do this many times a day. Collecting the data could be expensive if you measured every time you did it. Using a small sample (typically 6 or more), however, you can effectively measure and evaluate the process.
Calculate, plot, and evaluate the standard deviation (S) chart first. If it is "out of control," so is the process. If the S chart looks okay, then calculate, plot, and evaluate the X chart.
Please note: If you are asked by QI Macros for a "Subgroup Size," a subgroup is a group of measurements produced under the same set of conditions.
- Capability Suite - Capability, Stability and Data Normality Analysis in One
- XbarS chart template in Excel (XbarS Six Pack)