Six Sigma DMAIC Process - Control Phase - Control Chart Selection
Points to keep in mind while selecting a control charts:
Continuous Data: For continuous data we can measure the average and the variation, thus X bar &R (Range) or X bar and S (Standard deviation) can be used.
Attribute Data: For Attribute data we first have to determine what are we measuring – Defects or Defectives. In case we are capturing defective data then determine if we are sampling for subgroup of equal sample size or not. In case if we are capturing data for defects then determine if the opportunity for the defects are the same for each subgroup or not. Based on the above we need to select the appropriate chart.