Create NP Charts

How Do I Create an NP Chart in Excel Using SigmaXL?

NP-Charts

1. Open Attribute Data NP Chart Defectives.xlsx. The subgroup size is constant at 50. NP Charts (for Defectives) require a fixed subgroup size.


2. Select SigmaXL > Control Charts > Attribute Charts > NP. Ensure that the entire data table is selected. If not, check Use Entire Data Table. Click Next.


3. Select Defectives, click Numeric Data Variable (Y) >>; enter 50 for Enter Subgroup Size. Check Tests for Special Causes.
   


4. Click OK. The resulting NP-Chart is shown:
   
   This is a stable process, with no tests for special causes flagged.