# Control Charts Notations

Six Sigma – iSixSigma Forums General Forums General Control Charts Notations

Viewing 4 posts - 1 through 4 (of 4 total)
• Author
Posts
• #53599

Anonymous
Guest

Hi everybody

Do you know why in control charts calculations :

– c4 is noted… c4 (what means the “c” and what means the 4)?

– d2 is noted…. d2 (what means the “d” and what means the 2)?

– d3 is noted…. d3 (what means the “d” and what means the 3)?

– d4 is noted…. d4 (what means the “d” and what means the 4)?

– A2 is noted…. A2 (what means the “A” and what means the 2)?

– B3 is noted…. B6 (what means the “B” and what means the 3)?

– B4 is noted…. B4 (what means the “B” and what means the 4)?

– B5 is noted…. B5 (what means the “B” and what means the 5)?

– B6 is noted…. B6 (what means the “B” and what means the 6)?

I will have a class about SPC in a few month in my company. I have to make the mathematical proof of this coefficient (this point is ok) but i’m sure that my student will ask me where these notations comes from and i did not found any informations about it….

0
#190807

Robert Butler
Participant

You need to get a good book on quality control and do some reading. One possibility is Quality Control and Industrial Statistics – Duncan – 4th Edition – Table M in the back lists all of them, their mathematical definitions, and it points you to the source document.

0
#190854

Rohatgi
Participant

These are just notations used to represent sample size dependant constants.
Natural choice is Alphabets A,B,C, D etc. with 1,2,3,4…as subscripts.

There is no other meaning to it. Just as R is used to represent Range, MR is used to represent Moving Range

0
#190859

SOS
Member

Hi

You shall refer “Industrial Statistics” books by Duncan.