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Background documentationWECO Rules

 

The following table lists the Western Electric Company (WECO) rule numbers, which can be displayed on SPC charts with alarms. The {LIMIT} and {LENGTH} tags are replaced when the query for the chart is executed.

Rule Number

Description

1

Outside of control limits

2

{LIMIT} of {LENGTH} points above or below centerline

3

{LIMIT} of {LENGTH} points steadily increasing or decreasing

4

{LIMIT} of {LENGTH} points alternating trend direction

5

{LIMIT} of {LENGTH} in Zone A or beyond

6

{LIMIT} of {LENGTH} in Zone B or beyond

7

{LIMIT} of {LENGTH} points between +/- 1 sigma

8

{LIMIT} points not between +/- 1 sigma

9

Point outside the specifications

Note Note

Rules 1-8 are applicable for iSPCCharts whereas all 9 rules are applicable to i5SPCCharts.

End of the note.

See also:

iSPCChart Alarms

iSPCChart Upper Chart WECO Texts

iSPCChart Lower Chart WECO Texts