Capability Index.
Six Sigma – iSixSigma › Forums › Old Forums › General › Capability Index.
- This topic has 3 replies, 3 voices, and was last updated 12 years, 7 months ago by
Mikel.
-
AuthorPosts
-
November 10, 2009 at 2:20 am #52903
Why Cp=1 when specification spread is taken as 6s which is equivalant to 0.27 % out of spec. Is it not wise to take 5.15 s as this is equivalent to 1 %? Generally for R&R measurement it is equivalant to 5.15. This will definately more logical and ease out situation.
Regards
Pradeep Joshi0November 10, 2009 at 7:31 am #186719Why not 3.290? 5% is definitely easier and god knows we just want something easier.BTW 5.15 has not been used for GR&R for over a decade.
0November 10, 2009 at 8:10 am #186720just taking a guess from not really knowing =)
Capability Index 1 (3/3) were found to be at the time (1930 something) a good process and +/- 3 StDve were stated as sort of norm en lived ever since.
Probably if the index were to be invented today it would be 6/6=1?
0November 10, 2009 at 9:43 am #186721Actually goes back only to the 60’s.It has been fairly well demonstrated that if Cpm can be maintained >
1.33, it’s all you need.0 -
AuthorPosts
The forum ‘General’ is closed to new topics and replies.