The energy performance of steam boilers, such as the efficiency and the evaporation ratio can decrease along time because of the poor combustion, heat transfer fouling, poor operation, and low maintenance rate. The energy indicators assessment allows to observe the abnormal operational deviations to implement corrective action, so it is necessary to find out the level of efficiency in real time to evaluate the thermal performance, which is an obligatory requirement to implement the energy management program in the industry. As a contribution in the area of energy efficiency in steam boilers, the results of an applied research are presented, where the behavior of steam production and gas consumption as input variables were considered to apply the methodology and obtain the energy saving results on a boiler from 125.000lb/h steam capacity. The consumption and energy production control charts, the base and goal line, and base 100 indicators were calculated to facilitate the energy monitoring of the steam boiler for a period six month. Letting the application of the methodology to recognize saving opportunities starting from the analysis of variables that impact the energy consumption affected by different ways energy consumption of the company. The study showed a linear base with the form EB = 0.0595x + 0.988, with a linear correlation equal to R2 = 0.973 and a goal line EG = 0.0586x + 1.3814, with a linear correlation of R² = 0.97, which means statistical validity in the data collection. Additionally, the base 100 index was calculated to identify satisfactory the peaks of energy efficiency, showing efficiency and inefficiency in the process. The study shows that data reflected below the efficiency rate (100) are considered peaks of energy inefficiency, which means energy saving opportunities for operational control, maintenance management, production planning, besides the typical ones due to technological changes.