Report Builder - Supplier Quality

I am trying to create a report that will measure a Supplier's
Quality. My thought is to create a parts per million calculation by
using the Total Discrepent Quantity, associated with DMR's, and
divide by the Total number of pieces received for a given time period.

Does anyone use a report that measure Supplier Quality? If so, I am
curious how quality is measured?

Eric Christus
Whitewater Mfg
Version 5.00.340