MET $245$ Week $2,$ Lecture $3-4$: QC SPC $5$

g$)$ Calculate the short$-$term process capability index, Cp:

h$)$ Calculate the long$-$term process capability index, Cpk $($the $$off$-$center$$ index$)$:

i$)$ What can you conclude about the process capability, i$.$e$.$ capability of this machine $($and the tool

used$)$ to cut the keyseat to specifications? Next week you will see that six sigma capable

processes have capability indices Cp $=2$ or greater, and Cpk $=1\mathrm{.}5$ or greater. We all know that

six sigma is $$all the rage$$ in manufacturing, a goal that is distant to most manufacturers.

a$)$ The process is not capable.

b$)$ The process is extremely capable to make this dimension, well beyond six sigma capability.

Actually, the process looks unrealistically capable.

c$)$ No conclusion can be made about the capability of this process.

j$)$