np Chart Formulas
QI Macros Can Calculate Them For You!
Draw a np Chart using QI Macros
- Select your data.
- Select np chart on QI Macros menu.
- QI Macros will do the math and draw the graph for you.
Go Deeper
The np Chart is used to evaluate process stability when counting the number or fraction defective.
The np Chart is useful when it's easy to count the number of defective items and the sample size is always the same. Examples might include: the number of defective circuit boards per 100 or errors per each sample of 50 invoices.
Here is the formula used to calculate a np Chart.
Conforms with ANSI/ASQC B1, B2, B3 1996
Stop Struggling with np Charts!
Start creating your np Charts in just minutes.
Download a free 30-day trial. Get np Charts now!
The np Chart is just one of the tools included in QI Macros SPC Software for Excel.
Why Choose QI Macros Over Other Control Chart Software?
Fast and Easy to Use
- Works right in Excel
- Create charts in seconds
- Easy to customize & share charts
- Free Training Anytime
Proven and Trusted
- More than 100,000 users
- In More than 80 countries
- Five Star CNET Rating - Virus free
Affordable
- Only $369 USD
Quantity Discounts Available - No annual subscription fees
- Free technical support
