Process Screen, 1 value per subset, how is within sigma calculated?
Jun 12, 2019 1:32 AM(2065 views)
I have data that consists of groups of subgroups. Each subgroup consists of one value. When I run the process screening on it, I get an overall sigma (the sigma between the different subgroups) and a within sigma. I cannot figure out what this within sigma is. I would like to use the stability index in my analysis, but cannot figure out how it (or the stability ratio) is calculated. Where does this within sigma come from/how is it calculated?
For some reason i can not upload the process screening or the data table. I have them availableif they are necessary for answering my question.