Problems calculating the observed CP - Page 19, AIAG MSA manual 3rd edition

[Oskar_S]

Hello

I have just started to read aboaut MSA and started with the MSA reference manual (3 edithion AIAG) and I have som troubles following their calculations. On page 19

(CP)obs ^2= (CP)actual ^2 + (CP)msa ^2

For example if the measurement system cp indes were 2, the actual process would require a cp index greater than or equal to 1.79 in order for the calculated (observed) index to be 1.33.

When Im counting I got a different result.
(Cp)obs=sqrt(1.79^2+2^2)
=> Cp obs= 2,68 according to the manual it should be 1.33

 

[harry]

Re: Problems calculating the obs CP (pg 19, MSA 3rd edition manual)

If you have the first printing of 3rd edition, there are errors. Please check.

You could have made mistakes somewhere, see this post by Miner.

For details, check this thread: Cp Capability Comparison - Page 19 and 20 of the 3rd edition of the MSA manual

 

[Oskar_S]

Re: Problems calculating the obs CP (pg 19, MSA 3rd edition manual)

Thanks. I think I have lost almost 2 hours of my precious time just by redoing this calculation. But now I know its the manual fault.....