Hi, can someone tell me why I getting a strange Cpk value? I know that that if you get a negative ( - ) cpk is because your mean is above or under spec's limit, but what I getting is -1.00000. Do I nee to adjust the setting on Datapage...help......
Here is an example : Bore Dia Spec: 17.7 / 17.9 mm. Min found 17.37 / Max found 17.79mm. As you can see there is a lot of variation.
Thanks for the quick response. Yes, I'm sure that is wrong, what I did was I use Minitab, it came back with a very different Cpk valuer.....
Cpk is defined as the lower value of either CPU or CPL. If your average is lower than your lower spec limit of 17.70 then it is mathematically impossible to get a positive value. ((17.79+17.37)/2)=17.58
Here is an example : Bore Dia Spec: 17.7 / 17.9 mm. Min found 17.37 / Max found 17.79mm. As you can see there is a lot of variation.
Thanks for the quick response. Yes, I'm sure that is wrong, what I did was I use Minitab, it came back with a very different Cpk valuer.....
Cpk is defined as the lower value of either CPU or CPL. If your average is lower than your lower spec limit of 17.70 then it is mathematically impossible to get a positive value. ((17.79+17.37)/2)=17.58
