The supplier/product group pairings are split into four categories according to the level of interdependence with the Group: p category A: unavoidable supplier: the Group is highly dependent on the supplier for this product group; p category B: collaborative relationship: the PSA Group and its supplier rely strongly on each other for this product group; p category C: dependent relationship: the supplier relies strongly on the Group for this product group; p category D: competitive relationship: the Group does not rely on the supplier (there are many other suppliers for the purchase group in question) and the supplier does not depend on the Group for this product group.