Various rules
In addition to the use of the simple rule for the following settings:
 Within the control limits: whenever a part is measured that falls within control limits the perfectly centered process hypothesis is completely verified. No futher action is required.
 Outside of control limiits: whenever a part is measured that falls outside of the control limits the perfectly centered process hypothesis is not verified. The process must, therefore, be adjusted.
Using the rules defined above allows for variation detection in finer processes.
Graph  Description  Meanvalue chart decision  Range chart decision  
Controlled procedures
The curves and the oscillating R from each side of the mean. 2/3 of the points are in the central third of the chart. 
Production  Production  
Points outside of the limits
The last point traced surpassed the control limits. 
Adjusting the procedure
by the difference value that separates the point from the target value. 
Upper limit case
The shortterm capability deteriorates. It is necessary to find the source of this deterioration and intervene. There is a measurement error 

Upper or lower trend
7 consecutive points are above or below the mean. 
Adjusting the procedure
by the mean difference that separates the trend from the target value 
Upper trend case
The shortterm capability deteriorates. It is necessary to find the source of this deterioration and intervene. Lower trend case The shortterm capability improves. It is necessary to find the source of this improvement and maintain it. 

Increasing or decreasing trend.
7 consecutive points show a regular increase or a regular decrease. 
Adjusting the procedure
if the last point approaches the control limit of the difference that separates the last point from the target value. 
Ascending series case
The shortterm capability deteriorates. It is necessary to find the source of this deterioration and intervene. Descending series case The shortterm capability improves. It is necessary to find the source of this improvement and maintain it. 

1 point is close to the limit.
The last traced point within 1/6 of the edge of the control chart.

Confirm
by taking another sample immediately. If the point reappears in the central third – production. If the point is also close to the limits or outside of the limits, adjust the meanvalue of the two points 
