Control chart

Control chart is a type of time-based trend analysis tool used within Statistical Process Control.

It is also called a Process Behavior chart, renamed by Donald Wheeler in Understanding Variation, as he felt that “it is appropriate to use words that are more descriptive of what is intended.”

There are a few popular control charts:

Attribute data

• Proportions chart (p chart)
• Nonconforming chart (np chart)
• Units nonconforming chart (u chart)
• Subgroup nonconforming chart (c chart)

Variable data

• Individuals and Moving Range chart (I-MR or ImR and X-MR or XmR)
• Average and Range chart (X-bar and R)
• Average and Standard Deviation chart (X-bar and S)
• Estimated Weighted Moving Average (EWMA)
• Cumulative Sum chart (CUSUM)

Free Templates

• Attribute SPC Chart Templates for Excel and Google Sheets (p and u charts)
• Individuals and X-bar R Control Chart Template (manual data entry)
• Individuals SPC Control Chart Excel Template

Books

• Understanding Variation: The Key to Managing Chaos by Donald Wheeler
• Introduction to Statistical Quality Control by Douglas Montgomery