Predicting and analyzing misalignment defects during product design

The quality manufacturability (QM) of a design is defined as the likelihood that quality defects will occur during product manufacture. Clearly, some designs are more likely to have a lower production yield rate and/or higher quality management cost as compared to an alternative design. We have developed a new methodology called design for QM, which analyzes a design and predicts what quality defects could occur during manufacturing. One of the defect classes this method analyzes is misalignment between pairs of mating parts. In this paper, we provide a standard nomenclature for part misalignments, relate their occurrence to design features, and illustrate how the QM index is calculated.