Hello,

Can you please help me understand the following scenarios of a control chart:

1. If the value falls on the UCL (upper control limit) or LCL(lower control limit), (not above or below), is it considered to be "out of control"

2. If there are < 7 clustered points, above or below mean and within the UCL and LCL, is it considered "normal".  

3. What is an example of system being "out of control" or "needs caliberation" or "adjustment"

4. Above the mean and below the UCL or above LCL, is it considered to be +/- 3 sigma.