We describe the results obtained from long-term operation of 11 large power units at eight power stations after their previous traditional monitoring and control systems had been modernized with the use of Teleperm XP-R (TPTS-51 and OM-650) computerized automation system. The modernized automated process control systems were analyzed on the basis of a special questionnaire in which various aspects of estimating the modernization results were addressed: from adequacy of the adopted fundamental solutions to problems encountered during operation of the installed computerized automation systems. Experience gained from operation of the hardware used in the controller and upper control levels and from operation of application software, including process protections, automatic closed-loop control systems, step control programs, video frame subsystems, and calculation tasks. Appraisals given to the above-mentioned problems by power station specialists are analyzed. © 2013 Pleiades Publishing, Ltd.