CPK output

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • CPK output

    Even though I've been using DP for sometime now, I really don't know that much about it. Our QE has asked a question of why a particular TP of a circle CPK is so high ( this is while printing out in the Statistics Report )? I'll leave the one problems below. CPK.jpg


  • #2
    The Cpk is not high...it's the Ppk. That is interesting.

    Can you plug the data into another software (Excel, Minitab, etc)? If not, supply the data and I can plug it in real quick and see what Minitab gets.

    Comment


    • #3
      you shouldn't do SPC on position of holes. You will NEVER get a good result, even if it shows great.

      snap.jpg
      sigpic
      Originally posted by AndersI
      I've got one from September 2006 (bug ticket) which has finally been fixed in 2013.

      Comment


      • #4
        Originally posted by Matthew D. Hoedeman View Post
        you shouldn't do SPC on position of holes. You will NEVER get a good result, even if it shows great.
        Correct. And one cannot measure capability of the axis' because there is no tolerance.

        All one is showing with Ppk/Cpk is that your process can or cannot make it within the zone. It doesn't specify that it can actually make the part consistently in the same spot.

        Comment


        • qcfire65
          qcfire65 commented
          Editing a comment
          I will relay the message to our QE and thank you for your help all.

      • #5
        Did you look here :
        Capability calculations for True Position - PC-DMIS User Forum (pcdmisforum.com)
        ‚Äč
        Maybe it could help ?
        (the last post of VinniUSMC should contain a right version)

        Comment

        Related Topics

        Collapse

        Working...
        X