Same spread, same Cp: only Cpk notices the process moved9.79.89.91010.110.210.30246810normal fitLSLUSLmeasured diameter (mm)probability densitycentred: Cp = 1.47, Cpk = 1.47, 0 ppm out4000 partsnormal fit9.79.89.91010.110.210.3normal fitLSLUSLmeasured diameter (mm)shifted 1.5 sigma: Cp = 1.47, Cpk = 0.97, 1750 ppm out4000 partsnormal fitSame spread, same Cp: only Cpk notices the process moved