u Chart Formulas
u charts determine stability of "counted" data (e.g., errors per bill, dents in a car door, etc.) when there can be more than one defect per unit and the sample size varies.
Here is the formula used to calculate a u chart.
cᵢ = number of nonconformities
nᵢ = sample size
Conforms with ANSI/ASQC B1, B2, B3 1996
The u chart is just one of the tools included in the QI Macros for Excel SPC Software for Excel.
Why Choose QI Macros Over Other Control Chart Software?
- Only $299 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