Fixing a Control Chart
Hi,
I’m trying to elevate my control chart to the ‘next level’ by applying the Nelson 5 statistical rules. In other words, I want to be able to highlight the points on the graph that display the Nelson statistical rules. Would you be able to help assist?
The way I do this is to add a column where you test each rule (so I like helper columns, I like things to work). A formula in each column returns TRUE if the rule has been broken. You can either add one series to the chart for each rule and format each differently (to identify which rules were broken where), or add one final column which is true if any of the rules were broken and plot just this column.
Use slightly larger markers for the added data, and give them a color that draws attention.
Would you be able to post an edited data set just with the points and standard deviation? It would be easier to make suggestions and show what we mean without having to recreate the data.
Ok. I roughed something out showing my interpretation of John Peltier’s logic.
Chart showing how it looks when plotted