On Jul 1, 11:02 am, "Tony" <a_bu...@[EMAIL PROTECTED]
> wrote:
> It's not hard to see why Wheeler says that CUSUM is a chart that only
its
> mother would love ...
>
> Rather than jumping in blindly, it would be insightful to ask why your
> client wants to use these charts rather than Shewhart Charts.
>
> There is no need to "normalise the variance". Wheeler discusses this in
> great detail in the wonderful little book he has written on this topic
> "Normaility and the Process Behaviour Chart", SPC Press.
>
> Dr Tony Burns
>
Thanks for your reply. However, I am afraid I can't agree about CUSUM
charts being totally useless, as you imply. They were invented to
detect small/gradual changes in the process mean, and both my
(limited) experience, and that re****ted by others, shows that they do
achieve this objective quite well, in particular, better/faster/more
reliably than Shewhart Charts. My question was about the efforts made
to extend the CUSUM idea to monitor changes in process variance.
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