Sample Size

Section 3 Control Charts

Lesson S03-11

Text: Section 3 pages 64 – 72

Duration: 24 minutes

Sample Size Sensitivity

Our discussion now moves to the issue of sample size, although the term “sensitivity” is sometimes used. It will become evident why sample size controls the sensitivity of control charts. By sensitivity, we mean the ability of a control chart to detect change.

Control charts are supposed to detect change when change occurs. The question is, “what kind of change do charts detect?” Are all X̄ charts equivalent in their ability to detect changes?

Example: Ice Cream Filling Process

Sample Size Summary