Manufacturing statistical process control in the presence of multiple batch effects

A system for qualifying for use in an overall manufacturing process items produced by a bulk manufacturing process that has a plurality of batch effects, the system comprising:

• a test bed for measuring a quantifiable property of a sample of items from a collection of items produced by a bulk manufacturing process that has a plurality of batch effects;
• and
• an electronic computer comprising at least one electronic processor that executes instructions to perform operations comprising:
• developing a linear mixed model for the quantifiable property based on the measuring,
• determining a statistical process control standard deviation for the collection of items based on the linear mixed model,
• computing a statistical process control parameter from the statistical process control standard deviation, and
• determining that at least a portion of the collection of items conform to the statistical process control parameter;
• wherein the at least a portion of the collection of items are accepted and used in the overall manufacturing process.