WestgardRules.md

Process Control Chart Capability Options

Westgard Rules

Process Control Chart offers Capability options to control 5 Westgard Rules. They are,

1. Westgard 1S3
2. Westgard 2S2
3. Westgard RS4
4. Westgard 4S1
5. Westgard 10X

These rules can be optionally enabled or disabled; their Colors and Dot Sizes can also be adjusted through the capability options shown in Figure 1 below.

Westgard Rule Options - Custom Settings

Figure 1. “Westgard Rules” Settings.

Westgard Rule Samples

Following samples are provided as references. Out of control sequences based on respective Westgard Rules are boxed below to highlight them but Process Control Chart Visual does not draw these boxs for you.

Westgard 1S3 Sample

Figure 2. 1S3 - 1 value beyond 3*sigma from the mean.

Westgard 2S2 Sample

Figure 3. 2S2 - 2 consecutive values >, or <, 2*sigma from the mean.

Westgard RS4 Sample

Figure 4. RS4 - A difference between consecutive values > 4*sigma.

Westgard 4S1 Sample

Figure 5. 4S1 - 4 consecutive values >, or <, 1*sigma from the mean.

Westgard 10X Sample

Figure 6. 10X - 10 consecutive values >, or <, the mean.