Question

Problem 10-22 (Algo) C-Spec, Inc. is attempting to determine whether an existing machine is capable of milling an engine part that has a key specification of 5 + 0.09 inche. After a trial run on this machine, C-Spec has determined that the machine has a sample mean of 5.001 inches with a standard deviation of 0.030 inch. a. Calculate the cpk for this machine. (Round your answer to 3 decimal places.) Capability Index b. Should C-Spec use this machine to produce this part? Yes O No

Answer 1

Process capacity index is nothing but the statistical measure of process capacity to identify whether output is produced within customer's specification limits. The standard Cpk level is 2.0 for the six sigma process.

Process capacity is the number of times the process fits into the tolerance width. So, higher the value of Cp, the better the process.

PJUT Dato Problem 10-22 (solution) 5 USL = . : + 0·09 5 •03 cle LSL = 5 - 0.09 | : 471 0. - PK min USL - mean mean - LSL 3xo 3xo - min (5.09- 5.001 5.001- 4.91 3x 0·030 3x 0.030 min 0.089 0.091 0.090 0·0907 - min (0.989 , 1.011) = 10.989 / than I No is as Cpk is less incapable. so the process ber