Better understanding statistics and variability

[TILLAMOOK]

How do I know when I have a kiln out of whack versus "normal" variability?

[PhilM]

To determine if your kiln is "out of whack" (which could mean different things), you need to check to see if your kiln conditions (meaning the temperature and humidity and air) in the kiln is what you actually set at the controller (eg "Get what you set").  Hopefully you have a history of kiln performance  in terms of actual kiln conditions and lumber quality.  Being able to compare what happened today with how the kiln performed in the past is a good indicator of whether the kiln is "out of whack".   If the problem is perceived "excessive degrade", then you have to separate whether it is a kiln performance issue or a kiln schedule issue.  A history of the kiln's performance will help you figure that out.