Reference no: EM131550683

Question: Refer to the Jet Engine Visual Inspection case in

(a) When possible causes for out-of-control points on a control chart are addressed and physically eliminated, it is common practice to discard the data associated with those out-of-control points and recalculate control limits. Apply this thinking to part (e) of problem 27, assuming causes of the out-of-control points have been addressed (you should "throw out" July 16 and 25 and August 1 through 10-a total of 11 out of.

(b) Suppose the following data are obtained in visual inspection of final engine assemblies over the next three days:

(Partial inspection of final engine assemblies could possibly occur because of unforeseen labor problems. More than one engine assembly might be inspected on days 2 and 3 to, in some sense, make up for the partial inspection on day 1.) Using the information from (a) above, find control limits for nonconformance rates on these three days (do not use the number of non-conformances during these 3 new days to find the limits). Also give the center line and three plotted values (non-conformances per engine assembly inspected).

(c) Do your values from part (b) suggest process instability? Explain.

(d) Your center line should be constant across the three days represented in (b). Why is this?