• Raju replied to the topic Diamond polishing in the forum General 17 years, 1 month ago

    hai BTDT
    The sarine machine is an excellent tool to meassure but the limitation is it is done only after an operation ,as you know it is very difficult to repair a diamond.If we get the job done @ first time we are also saving the yield.
    Thanking you for your interest and valueable suggetion
    regards raju

  • Raju replied to the topic Diamond polishing in the forum General 17 years, 1 month ago

    Hai and thnks everyone responded to my topic.
    I am still not sure how to implement 6 sigma in this industry.
    A breif to who new to diamond industry,We are working with 3 to 6mm diameter diamonds.the accuracy needed in microns and while polishing on the machines it is difficult to check the angle and size.

  • John
    No, I guess there is a difference. It is not obtaining Cp or Cpk on the univariate first and weighting them by PC’s to get a multivariate Cp. It is about obtaining Cp or Cpk for each principal component first and combining them to get one overall Cp. This procedure exploits PCA properties – each individual principal component will be n…[Read more]

  • I was thinking about this problem, generally, conventional application of statistical methods may not be appropriate when the process is operating at near zero defects level and there has been some work in this area and I found a book which has been published recently on this issue (attached the link). I haven’t gone through this yet hence I can’t…[Read more]

  • Marc
    Thanks for the feedback. The document is now attached.

  • PankajI have enclosed a presentation on this topic which may help you to understand better. If you are measuring all those CTQ’s or variables (i.e. Diameter, the perpendicularity and surface finish) of a component and you have this data for atleast sufficient number of components (around 30) then you can try this procedure mentioned in the…[Read more]

  • I guess you can try using a multivariate process capability index covering all the quality attributes your are interested in. The method mentioned in this article {Wang et al Using Principal component analysis in process performance for multivariate data. International Journal of Management Science 2000;185-194} worked well for my situation…[Read more]

  • It seems like a full 4X3 factorial design with two replications. What is the response variabe? Is it continuos? If it is, then you can analyse using standard full factorial model up using ANOVA technique. It is a standard analysis you can see in any of the statistical software.