Control charts are used during the Control phase of DMAIC methodology. Control charts, also known as Shewhart charts or process-behavior charts, are a statistical process control tool used to determine if a manufacturing or business process is in a state of control. If analysis of the control chart indicates that the process is currently under control, then no corrections or changes to process control parameters are needed. Moreover, data from the method can be used to predict the future performance of the process. If the control chart indicates that the process is not in control, analysis of the chart can help determine the sources of variation, as this will result in degradation of process performance.
There are many packages in R, which can be used for analysis related to Six Sigma. Here, we will go through
qccpackage (R package for statistical quality control charts) and learn “How to create control chart (to know whether the process is in control)”.
Control charts are great for telling if a process has changed in some important way—if your machine is boring holes outside of tolerances, if your busy web server is getting closer to the breaking point, etc.