Del is correct about the v-mask. Its useful for determining if a process
change is neccesary. And yes, the lines are straight, and actualy come to a
point off the chart. If any results of the cusum show outside the lines, then
something has occured. I just was wondering if anyone knows the formula to
make it work on excel.

"JerryA" wrote:

Anyone know how to take a Cusum chart and plot a v-mask on it?