# Need to Know Westgard Rules for Levey Jennings Charts?

## Westgard rules are built into QI Macros so you don't need to memorize them.

Westgard Rules are used with Levey Jennings Charts in laboratories. They use a combination of traditional rules and some unique rules not used in other rule sets.

Draw a Levey Jennings chart using QI Macros:

2. Select Control Charts > Special > Levey Jennings on QI Macros menu.
3. QI Macros does the math and draws the graph for you!

### List of Five Westgard Rules

Westgard rules include Western Electric rules 1, 2, and 4, Nelson's Rule 5 and a unique rule #9.

1. One point above UCL or below LCL (13s)
2. Two points above/below 2 sigma (22s)
*Westgard Rules state that 2 out of 3 points above/below 2 sigma can be Above AND Below the centerline*
3. Eight points in a row above/below the center line (8x), note: this rule will catch 9-12x
4. A trend of seven points in a row increasing or decreasing (7t)
5. Four points above/below 1 sigma (41s) or two points in a row with one above and one below 2 sigma (R4s).

Westgard rule #9 is unique and is not included in other control chart rule sets.

### Control chart rules available in QI Macros add-in for Excel

QI Macros use Montgomery's Rules as the default. However, you can easily switch to the Westgard Rules using the QI Macros menu.