posted 03 May 2001 11:18 AM              

---

Could someone please describe to me what statistical index Cmk is, what it means, and how to calculate it.

Many Thanks SteveT

IP: Logged

Posts: 20
From:Normandy, TN 37360
Registered: Mar 2001

posted 03 May 2001 12:47 PM               

---

I do not know about Cmk, but Cpmk is defined as:

Cpmk = (USL ö LSL)/(6*(sqrt(StandardDeviation^2+(mean ö T)^2)))

Where T = Target Value.

This link http://www.asq.org/pub/jqt/past/vol32_issue4/qtec-440.pdf gives some additional info. This is a PDF file, so you will need Acrobat Reader to access it.

Hope this helps.

Regards,
dWizard

------------------
I was better but I got over it.

IP: Logged

Posts: 20
From:Normandy, TN 37360
Registered: Mar 2001

posted 03 May 2001 12:54 PM               

---

...what it means...

Ooops. Forgot. Cpmk is used when the tolerances are not symmetric about the target.

Regards,
dWizard

------------------
I was better but I got over it.

IP: Logged

Posts: 26
From:Jeffersonville, IN
Registered: Dec 2000

posted 03 May 2001 02:29 PM               

---

Cmk is defined as a capability index for a stable machine. It uses the same formula as Ppk.
Cmk is a short term study of a machine capability. Whereas Ppk is a short run study for a process.

IP: Logged

Posts: 20
From:Normandy, TN 37360
Registered: Mar 2001

posted 03 May 2001 02:56 PM               

---

See Also:

https://elsmar.com/ubb/Forum10/HTML/000067.html

https://elsmar.com/ubb/Forum10/HTML/000068.html

https://elsmar.com/ubb/Forum10/HTML/000001.html

https://elsmar.com/ubb/Forum10/HTML/000028.html

https://elsmar.com/ubb/Forum10/HTML/000095.html

https://elsmar.com/ubb/Forum10/HTML/000156.html

https://elsmar.com/ubb/Forum10/HTML/000160.html

Regards,
dWizard

[This message has been edited by dWizard (edited 03 May 2001).]

IP: Logged

Posts: 622
From:Lapeer, MI USA
Registered: Oct 2000

posted 03 May 2001 03:06 PM               

---

Thanks for the link Don, it's a good read.

ASD...

IP: Logged

Posts: 12
From:Landskona, SkŒne, Sweden
Registered: May 2000

posted 07 June 2001 04:03 AM               

---

Ain't Cmk=revised rates of machine capability and calculates by the formula:

Cmk = 2((UTL-Mean)/(Xmax-Xmin))
Cmk = 2((LTL-Mean)/(Xmax-Xmin))
Cmk = the lowest value of above formula

Is this incorrect?

------------------
/Best wish Narfeldt

[This message has been edited by narfeldt (edited 07 June 2001).]

IP: Logged

All times are Eastern Standard Time (USA)