In Reply to Parent Post by Discordian
A customer told us that they are accepting of RSS when developing tolerances.
I've never heard of it until today.
Googled, found some equations, found some papers on the internet, dug around here for some threads but I'm still not entirely sure how it works.
Does anyone have a real life example of RSS method?
I have a training example I use for the red bead experiment. Split the paddle into two halves, and count each half as two different sources of variation. If you average 10 red beads for the whole paddle, each half will average 5 red beads. If we assume the number of red beads in the paddle is Poisson (or you can physically do this and calculate the standard deviations), the standard deviation for each half is the square root of 5.
Let's add the two numbers together. We should average 10 with a square root of 10 as the standard deviation. Indeed, if I add the square of the square root of 5 (which is 5) to the square of the square root of 5 (which also is 5), I get 5 + 5 = 10. I then take the square root of 10 and indeed get the expected answer.