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control chart violates the:
A. rules of seven
B. rules of eight.
C. Standard deviation rule.
D.3-sigma rule.
We have8 control chart rules listed in the table below. If we have any case of the ones below we should take an action
Control Chart Rules
Rule
Rule Name
Pattern
1
Beyond Limits
One or more points beyond the control limits
2
Zone A
2 out of3 consecutive points in Zone A or beyond
3
Zone B
4 out of5 consecutive points in Zone B or beyond
4
Zone C
7 or more consecutive points on one side of the average (in Zone C or beyond)
5
Trend
7 consecutive points trending up or trending down
6
Mixture
8 consecutive points with no points in Zone C
7
Stratification
consecutive points in Zone C
8
Over-control
consecutive points alternating up and down
The control chart and its zones are shown in below diagram
In our case in this question we have8 consecutive points on one side of the average in zone c which violates the rule its name ZONE C which is number4 in the table. This is considered a small shift in the process and can be maintained with little adjustments.
Option (A) rules of seven ----------