A method of automatically determining whether an unmonitored portion exists in a utility system, comprising: determining a hierarchy of the utility system, the hierarchy indicating how a number of intelligent electronic devices (IEDs) are linked to one another in the utility system, each of the IEDs monitoring one or more characteristics of a utility; automatically storing a data representation of the hierarchy; identifying, from the hierarchy, a parent IED in the hierarchy that is directly linked to at least one child IED; identifying, from the hierarchy, all of one or more child IEDs that are directly linked in the hierarchy to the parent IED; receiving from the parent IED a measured quantity, P P, of the characteristic of the utility measured by the parent IED; receiving from each of the one or more child IEDs respective measured quantities of the characteristic of the utility measured by each of the one or more child IEDs; adjusting the measured quantities measured by the parent IED and by the one or more child IEDs as a function of respective measurement errors associated with the parent IED and with the one or more child IEDs to produce respective error-adjusted quantities; calculating a difference between (a) the error-adjusted quantity associated with the parent IED and (b) the sum of the error-adjusted quantities associated with the one or more child IEDs; based on the error-adjusted quantities, determining whether an unmonitored quantity exists in the utility system, and, if so, storing an indication that a virtual device directly linked to the parent IED exists in the hierarchy, wherein the determining whether the unmonitored quantity exists in the utility system includes determining whether the calculated difference is within an error tolerance, and, if not, carrying out the storing; and storing the unmonitored quantity and an indication that the virtual device is consuming or producing the unmonitored quantity. determining a hierarchy of the utility system, the hierarchy indicating how a number of intelligent electronic devices (IEDs) are linked to one another in the utility system, each of the IEDs monitoring one or more characteristics of a utility; automatically storing a data representation of the hierarchy; identifying, from the hierarchy, a parent IED in the hierarchy that is directly linked to at least one child IED; identifying, from the hierarchy, all of one or more child IEDs that are directly linked in the hierarchy to the parent IED; receiving from the parent IED a measured quantity, P P, of the characteristic of the utility measured by the parent IED; receiving from each of the one or more child IEDs respective measured quantities of the characteristic of the utility measured by each of the one or more child IEDs; adjusting the measured quantities measured by the parent IED and by the one or more child IEDs as a function of respective measurement errors associated with the parent IED and with the one or more child IEDs to produce respective error-adjusted quantities; calculating a difference between (a) the error-adjusted quantity associated with the parent IED and (b) the sum of the error-adjusted quantities associated with the one or more child IEDs; based on the error-adjusted quantities, determining whether an unmonitored quantity exists in the utility system, and, if so, storing an indication that a virtual device directly linked to the parent IED exists in the hierarchy, wherein the determining whether the unmonitored quantity exists in the utility system includes determining whether the calculated difference is within an error tolerance, and, if not, carrying out the storing; and storing the unmonitored quantity and an indication that the virtual device is consuming or producing the unmonitored quantity.