A
Arizona1
Fantastic Website for sharing Quality Analysis Info- Sometimes it helps just to bounce an idea off others when you are not surrounded by statistical geniuses.
Here is a simple 125 piece part Capabilty excel sheet to calculate Cpk
Simple 125 piece part Capabilty Excel .xls sheet to calculate Cpk
Fantastic Website for sharing Quality Analysis Info- Sometimes it helps just to bounce an idea off others when you are not surrounded by statistical geniuses.
Here is a simple 125 piece part Capabilty excel sheet to calculate Cpk
S
supreecha
I have just simulated 125 supgroup And 3 Key Process Parameters , after that Calibration sheet by Minitab .
D
Darius
First, The formulas for average and stdev just take the first 75 data, not 125 as it should
for example
bad C11=AVERAGE(C13:C82);D11=STDEV(C13:C182)
good C11=AVERAGE(C13:C75,E13:E75); D11=STDEV(C13:C75,E13:E75)
The same for H11,I11; M11,N11
Second, The formula for Cpk (really ppk)
bad E11=((B11-C11)/(3*D11))
good E11=MIN(B11-C11,C11-C7)/(3*D11)
The same for J11,O11
That's the reason, why it didn't work for J11 (you were taking in account only the upper limit, it must be the least of the difference of upper and lower with the average)
for example
bad C11=AVERAGE(C13:C82);D11=STDEV(C13:C182)
good C11=AVERAGE(C13:C75,E13:E75); D11=STDEV(C13:C75,E13:E75)
The same for H11,I11; M11,N11
Second, The formula for Cpk (really ppk)
bad E11=((B11-C11)/(3*D11))
good E11=MIN(B11-C11,C11-C7)/(3*D11)
The same for J11,O11
That's the reason, why it didn't work for J11 (you were taking in account only the upper limit, it must be the least of the difference of upper and lower with the average)
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