Patent ID: 7539585

Claim:
A system for identifying manufacturing events significant to a value of a given target production quality of an item, comprising: machine-readable storage medium storing (1) a manufacturing history record for each item of a group of items, each record having a unique item identifier, a target value representing a measured value of a given target, and a manufacturing event vector representing a plurality of different manufacturing events and whether or not each of the manufacturing events occurred in the manufacturing of the item; (2) machine-readable instructions for representing each of said manufacturing events as a step-tool pair representing a particular manufacturing step and a particular manufacturing equipment; (3) machine-readable instructions for forming each manufacturing event vector for each item to include a plurality of step-tool pair attributes, each attribute having a value representing whether or not the step-tool pair was applied in the manufacturing of the item; (4) machine-readable instructions for generating a binary decision rule, the binary decision rule being in a form IF/THEN/ELSE, said generating including selecting a pattern of manufacturing events such that an in-pattern statistic differs by at least a given significant threshold from a global statistic, the in-pattern statistic being a statistic of the target value for all items of the group having the pattern of manufacturing events in the item's fabrication history record and the global statistic being the same statistic of the target value for all items of said group; and (5) machine-readable instructions for identifying a pattern of said significant manufacturing events, based on said binary decision rule.