How to use the control chart for monitoring the quality control data, determining whether the data are out of control, and also solving the problems

The equipments, chemicals, and testing conditions have to be checked whether they remain in  appropriate condition. A duplicate check of the quality control (QC) sample would be done to investigate the nonconforming work. There are 2 possible cases:

1.) If the result is outside the “out of control” area, plot the control chart with a new result of the QC sample and the previous result (or the out-of-control result). Then, record other activities and analyze the next sample.

2.) If the result is inside the “out of control” area, stop analyzing the sample, investigate the sources of errors, and take the corrective actions. Then, plot a new control chart and record all data and activities.