SPC alerting rules and charts

[phuongquan]

• would probably need to plot limits and colour “special cause” points for this to be intelligible. New plot type=”xmr”?
• NHS plotthedots does 3-4 types of special cause points
• could consider something simpler like runcharter, with or without auto rebasing
• Also see R Quality Control Charts - ggQC v0.0.31