1. A computer implemented method for optimizing a composite load disaggregation in an electrical environment, the method comprising: performing a factor-graph analysis on one or more input variables to generate confidence measures for one or more appliances in the electrical environment, wherein the confidence measures indicate at least one appliance from the one or more appliances being switched on at an instance, wherein the factor-graph analysis is implemented based on matrix formulation of blind source separation or based on load block diagram; retrieving contextual information impacting the usage of the one or more appliances from a contextual information database; and optimizing the composite load disaggregation, by applying one or more rules to the confidence measures and to the contextual information for identifying at least one appliance from the one or more appliances, and wherein conflicts in decision of identifying least one appliance from the one or more appliances is resolved based on the optimized composite load disaggregation through the factor-graph analysis.