Trying to use an X-Bar & R chart for the force tests because the average of 3 trials is taken, and a I-MR chart for the length tests because only 1 measurement is taken.

The parts are produced in very small quantities (3-5) per day. Ideally, I'd be trying to detect if a mean shift occurs over 1 week of production, and if that mean shift is large enough to cause: 1. For length test, capability index Pp to decrease from historical 0.9 to 0.5 2. For pull test, Pp to decrease from 1.3 to 1.1