How is Cpk /Ppk value calculated in Minitab since I have subgroup size of 1

S

statistic

I'm confused about this sample size/soubgroup choosing in Minitab.
I'm in that lucky situation that out test equipment is logging every test point so what I do is taking I'm taking a whole week production (thousand pcs+ or I may take a single day production of 200pcs) plotting it using six pack in minitab and comparing it to the last week production. I see every individual value (soubgroup size 1) and since I know the system I can recognize different sources of variation which I try to eliminate. I also know that if the data is not normally distributed then something is wrong.This is simple logic and I feel this is the best way to view data since I can see everything on a time scale. Now the question is simple. How is CPC /PPK value calculated in minittab since I have soubgroup size of 1 and I'm I doing things wrong.
thanks
 
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