Statistical methods in manufacturing
When we need to make improvements and use statistics is the real 6sigma work – improving process stability. The outcome of your efforts is the improvement in the variance, so you need to consider using the F-test or my favourite, the ANOVA. The benefit of using ANOVA (I mean the one-way ANOVA) is simple: you spend time setting up your Excel calculation table once, but later, with minor adjustments (if any) you can run a quick analysis on multiple sets of samples. Furthermore, It’s the best tool to investigate process stability over the production run: start-up, steady run, after a material change, or around stoppages.