I'm creating a process control chart with reference lines for 3x stdev, process mean, etc. I've done that but now I need help with displaying trending. I'm specifically looking for things like identifying seven consecutive points on either side of the process mean or two out of three consecutive points more than 2x stdev from the process mean. I'm guessing this would involve identifying those points then applying conditional formatting of some sort, but I'm not sure. Any ideas?
The formulae you wouldneed for this kind of analysis are combinations of the above / below and the range formulas. EG for the 7 consecutive points above the [upper] line the expression would resemble this:
Changing this expression in a line chart to symbol only would place a symbol at the point where 7 consecutive points are above your "upper" expression. You can also combine it with the count() function to identify where 3 out of the last 5 etc have been above the line.
