The By Part graph shows all of the measurements taken in the study, arranged by part. The measurements are represented by dots; the means are represented by the circle-cross symbol. The blue line connects the average measurements for each part.

Ideally,

·    the multiple measurements for each individual part will vary as little as possible (the dots for one part will be close together)

·    the averages will vary enough that differences between parts are clear

For the parts data, the measurements for part 10 vary quite a bit. This variation may be due to the system's (operator and/or gage) inability to consistently measure that part. The averages also vary significantly. This should occur because the parts chosen for the study should represent the entire range of possible parts.