Capability indexes for the waterproofing process, continued. We could improve the performance of the waterproofing process discussed in the previous exercise by making an adjustment that moves the center of the process to μ = 2500 mm, the center of the specifications. We should do this even if the original specifications remain in force, because this will require less sealer and therefore cost less. Suppose that we succeed in moving μ to 2500 with no change in the process variability σ, estimated by s = 383.8.
a) What are Cp and Cpk with the original specifications? Compare the values with those from part (a) of the previous exercise.
(b) What are Cp and Cpk with the tightened specifications? Again compare with the previous results.