Hi, My issue is we are using Anova but discovered that the number of distinct catagories (Minitab 19) is 1, no matter what I do, I have had to deconstruct our previous SPC employees workings out to try and reconstruct it, our guide states to use Anova but when I use Anova the number of distinct catagories is always 1. Today I changed to X bar & R chart which then gave 43 distinct catagories. Will I be ok using X bar & R from now on rather then Anova. This is for fluid testing if that helps.