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Percentage conversion

Six Sigma – iSixSigma Forums Old Forums General Percentage conversion

Viewing 9 posts - 1 through 9 (of 9 total)
  • Author
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  • #66976

    “Ken”
    Participant

    John,

    Do you desire to convert a process yield value or percent defective into a Sigma value?

    Ken

    0
    #66977

    Gary Cone
    Participant

    John,

    There are tables published for this in almost everything writen by Mikel
    Harry or Motorola. If you do not have easy access to these, you can use a
    normal table to get the same. The conversion is to get the z value from the
    table and add 1.5. For example, if you are at 1350 defects per million
    opportunities, the corresponding z value is 3, add 1.5 for a sigma value of
    4.5. The 1.5 is the infamous 1.5 sigma shift.

    Gary Cone

    0
    #27389

    Tierradentro
    Participant

    Is there anyway to convert percentages alone into sigma ratings, or is there a chart avilable somewhere?
    Thanks everyone….John

    0
    #66986

    Praneet
    Participant

    Hi John
    There are tables available on the internet which will help you out with finding out your Sigma value from Percentage. However I would like to share a ready reckoner which I use. Hope you find this useful

    % age DPMO Sigma
    69.15 308537 2
    93.33 66807 3
    99.38 6210 4
    99.97 233 5
    99.993 3.4 6

    Regards

    0
    #66989

    Tierradentro
    Participant

    I am looking for a percent defective into a sigma value. Do you know where on the internet that a table may exist to print out? Thanks for all your help.

    0
    #66990

    Tierradentro
    Participant

    Thanks for the help! I already have several chrts and tables but I cant seem to be able to find one from a percent to sigma.( Such as 99.9999, 99.9998, etc….)much like the general sigma conversion tables for errors per 10,000 or per million. Thanks agian ! John

    0
    #66993

    Mendoza
    Member

    You could try to make a table in Excel, using the NORMSINV function.

    You have to calculate your DPMO, from your percentage.
    DPMO = 1 – Percentage
    then, calculate your Sigma
    Sigma = -NORMSINV(DPMO) + 1.5

    You have to select diferent cells, like any other function in Excel, I only was trying to explain the equations you have to do in Excel.

    I think this could help you,

    0
    #66994

    Gary Cone
    Participant

    The first forty values:

    99.9992 5.821336746
    99.9991 5.784083843
    99.999 5.765457392
    99.9989 5.74683094
    99.9988 5.728204489
    99.9987 5.709578037
    99.9986 5.690951586
    99.9985 5.672325134
    99.9984 5.663011909
    99.9983 5.644385457
    99.9982 5.635072231
    99.9981 5.61644578
    99.998 5.607132554
    99.9979 5.597819328
    99.9978 5.588506103
    99.9977 5.574536264
    99.9976 5.565223038
    99.9975 5.555909812
    99.9974 5.546596587
    99.9973 5.537283361
    99.9972 5.527970135
    99.9971 5.523313522
    99.997 5.514000297
    99.9969 5.504687071
    99.9968 5.497702152
    99.9967 5.490717232
    99.9966 5.481404006
    99.9965 5.476747394
    99.9964 5.469762474
    99.9963 5.462777555
    99.9962 5.458120942
    99.9961 5.448807716
    99.996 5.444151103

    Use the NORMSINV function in Excel as suggested.

    0
    #67038

    John Venegas
    Participant

    Thanks for the help! I now have the right idea…..your help is greatly appriciated.

    John

    0
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