A method, comprising: selecting, with a processor (10, 230), data records received from a plurality of data sources, the data records comprising distribution transformer load data, wherein at least some of the data records are in a plurality of different data formats; converting the data records in the plurality of different data formats into a pre-defined data format and populating a database (20, 260) with the converted data records using the processor; filtering, with the processor, the data records in the database by using a predetermined criterion and matching each of the filtered data records with one of a plurality of distribution transformers; transforming the matched data records to a plurality of predictor variables with the processor by calculating values of the predictor variables from the matched data records, wherein the plurality of predefined predictor variables are designed to reduce a data record volume; selecting, with the processor, a subset of the plurality of predefined predictor variables, wherein the predictor variables are selected according to a correlation test result indicating how much one of the predefined predictor variables is related to another one of the predefined predictor variables and how much one of the predictor variables is related to the historical outcome of a heavy load and/or overload; training, testing and tuning a model based on the selected subset of variables and a subset of matched data records, the model for providing a heavy load pre-warning and/or overload pre-warning for distribution transformers; forecasting at least one of heavy load or overload for each of the plurality of distribution transformers in a predetermined region based on the model to provide the heavy load pre-warning or the overload pre-warning for the distribution transformers in the predetermined region; and displaying the forecasted heavy load or overload for the plurality of distribution transformers in a user interface for upgrading the distribution transformers and/or generating a system alert for the distribution transformers. selecting, with a processor (10, 230), data records received from a plurality of data sources, the data records comprising distribution transformer load data, wherein at least some of the data records are in a plurality of different data formats; converting the data records in the plurality of different data formats into a pre-defined data format and populating a database (20, 260) with the converted data records using the processor; filtering, with the processor, the data records in the database by using a predetermined criterion and matching each of the filtered data records with one of a plurality of distribution transformers; transforming the matched data records to a plurality of predictor variables with the processor by calculating values of the predictor variables from the matched data records, wherein the plurality of predefined predictor variables are designed to reduce a data record volume; selecting, with the processor, a subset of the plurality of predefined predictor variables, wherein the predictor variables are selected according to a correlation test result indicating how much one of the predefined predictor variables is related to another one of the predefined predictor variables and how much one of the predictor variables is related to the historical outcome of a heavy load and/or overload; training, testing and tuning a model based on the selected subset of variables and a subset of matched data records, the model for providing a heavy load pre-warning and/or overload pre-warning for distribution transformers; forecasting at least one of heavy load or overload for each of the plurality of distribution transformers in a predetermined region based on the model to provide the heavy load pre-warning or the overload pre-warning for the distribution transformers in the predetermined region; and displaying the forecasted heavy load or overload for the plurality of distribution transformers in a user interface for upgrading the distribution transformers and/or generating a system alert for the distribution transformers.