Page 124 - The Six Sigma Project Planner

DPMO = 1,000,000 5 = 5,000 (Equation 2)
1,000

The DPMO for a characteristic is measured as the process average DPMO.
Poorly chosen opportunity metrics can lead to “denominator management”—
manipulation of the measurement system. For example, the opportunity metric for
complete electronic units delivered to final assembly should be the number of units, not
the number of solder joints in the units. A proper denominator reflects the process
being measured, not an earlier process or subprocess. For example, if the process is
creating solder joints, then solder joints are a proper opportunity measure. If the process
is placing circuit boards into an electronics assembly, then we would count circuit
boards, connectors, fasteners, etc. but not the constituent elements of these parts.

If you find that games are being played with the measurement system, list it as an issue
to be resolved by the project sponsor, process owner, or management. If the issue is
serious enough, consider classifying the project as “Stalled” until it is resolved. Six
Sigma can’t function in an environment where honest measurements are not available.

107