1. An apparatus having a computer readable storage medium on which is embedded one or more computer programs, the one or more computer programs implementing a method of maintaining an electronic stock ledger for a grocery store having a legacy computer system, the legacy computer system having multiple distant operational databases, the one or more computer programs comprising a set of instructions for: creating an electronic interface using the legacy computer system; creating an electronic data model using the legacy computer system; creating at least one process rule using the legacy computer system; selecting a product type and a type of product information regarding the selected product type to extract from the operational databases having at least one of sales information, inventory information and margin information; extracting product information regarding the selected product type and the selected type of product information from at least one of the operational databases; determining an original location within the at least one of the operational databases from which the extracted product information was extracted; determining a destination location within the central database which the extracted product information will be loaded; loading the extracted product information into the central database at the destination data location, using the electronic interface created at the legacy computer system; recording a new data set with the extracted product information using the data model and the at least one process rule created at the legacy computer system; and enhancing the new data set with the extracted product information in a master file set of data in the central database.