Re: FW: Cause source - system v. employee

[Stein Smaaland <smaaland@sys.no>]

                      Oslo, April 1st, 2002

Thanks, Wayne, for, March 29th, answering
further on the third question of my mail
dated March 8th;
>> 3) Sorry I do not understand why a special cause
>> variation should occur immediately following
>> the change? Have I missed something?

Your closing explanation March 29th;
>If you attempt a change to a system
>and do not see a resulting data change
>on a control chart, there is no
>evidence to support the change as effective.

In thinking through your answer, yes, I
started to feel the light... But. I have
also myself experienced that the change
which becomes visible on the chart,
following a well thought-through,
implemented process improvement, was
NO special cause variation, i.e.
no registration outside the process
lines, and no (or almost no) changed
central line (when recalculated later),
BUT ONLY less variation. (One example
from a Norwegian hospital; the time
used by the different departments in
answering phones set over by the
switchboard).

And this is also another, valid evidence
of a change having occurred, right?

Still learning
Deming Scandinavia
Stein
(stein.smaaland@deming.no)
*** The Quality of a SYStem ****