Controlled Variation
Variation that
DOES appear to have a steady and uniform pattern of variation during a
certain period of time. Controlled Variation maybe random at times
throughout it's life. It is believed to
be inherent to the design, process, or
procedure. This type of variation is considered satisfactory or expected.
Controlled Variation is sometimes referred
to as common cause, (Opposed to special
cause).
Uncontrolled Variation
Variation that appears DOES NOT to have any
steady or uniform pattern of variation during a certain period of time,
and thus is considered unpredictable.
Uncontrolled Variation maybe referred
to as special cause, (Opposed
to common cause).
