terms u201c product lot u201d u201c product run u201d u201c run of workpieces u201d etc are used interchangeably to describe a set of workpieces subjected to a manufacturing process process 14 may include any manufacturing process that operates on one or more workpieces contained in product lot 12 common processing examples include but are not limited to semiconductor processing stepper operations such as those used in lithography process 14 is implemented using u201c set points u201d 16 that were determined based on a selected rule 11 determined by data analysis system 18 set points 16 may be defined as any operational settings or conditions utilized by process 14 for example set points 16 may include dosage settings in a semiconductor processing step set points 16 are determined based on feedback data 20 that was obtained from previous processing operations in any manner known in the art data analysis system 18 includes a plurality of rules 19 e g rule 1 rule 2 rule n that can be applied to feedback data 20 to u201c filter u201d the data each of the rules 19 provides search criteria for examining historical feedback data 20 typically the rules are ordered from best to worst such that first rule provides the highest level of confidence the second rule provides the second highest level of confidence etc for instance.