1. A method for performing surveillance of an asset, said method comprising the steps of: populating a memory means with a plurality of different estimation models; obtaining a current data vector correlative to current asset operation wherein the current data vector is comprised of current data vector values; selecting an estimation model set from the plurality of different estimation models as a function of the current data vector; apportioning the current data vector values to the selected estimation model set by separating the current data vector values into a plurality of separated current data vector values and providing at least one separated current data vector value to at least one estimation model in the selected estimation model set; determining at least one estimated data vector value from each estimation model in the selected estimation model set for which at least one separated current data vector value is apportioned for obtaining an estimated data vector; and using the estimated data vector for performing asset surveillance.