The article forms and substantiates the application of control charts for the method of extending the service life of the source of ionizing radiation (SIR). An algorithm for its aim was developed. The main types of con- trol charts and the features of their application were considered. A methodology for constructing a cusum map for extending the service life of SIRs based on the results of their calibrations, as well as a methodology for checking the results of SIR calibration for statistical controllability, were developed. Extrapolation methods were considered, and the method of least squares was chosen as the most optimal for this technique.