Question

There are very few times when you should start to investigate a process once you have established Statistical Process control (SPC), and the process is considered to be under control. What is the main reason you should investigate?

Question 17 options:

Behavior is normal

A single plot falls outside the control limits

A large number of plots are on or near the center line

3 out of six values are above the central line

There is no real trend in any direction

Answer 1

The main reason you should investigate is:
There is no real trend in any direction.