We can tell a great deal about a process by looking at:
- any patterns in the plotted data
- the relationship between the plotted data and the Control Limits
For example, we can ask:
- Is the process producing any steel beams which are too long or
- Is it producing lots of beams longer or shorter than 105cm (i.e.
the customer's desired length)?
- Is each beam coming off the press a little longer (or shorter) than
the one before?