Abstract: Data about first and second products are loaded into a data processor. The first product data relate to the movement of the first products through a first product supplier, and the second product data relate to the movement of the second products through a second product supplier. Definitions of product grouping of the first and second product suppliers are also loaded into the data processor. The first and second product data and links between the first and second products and the product groupings of the corresponding first and second product suppliers are stored. Access to the stored first and second product data is permitted by a third party, but the access is restricted by product supplier and/or by product grouping.