The supply chain is tiered in that supply side and demand side can be organised into groups of partners with which we deal. Thus if we place an assembler such as the Ford plant at Valencia as the focal firm, buy side comprises tier 1 sup-pliers of major parts and subassemblies who deliver directly to Ford, while tier 2 suppliers deliver to the tier 1s, etc. On the sell side, Ford supplies to the national sales companies as tier 1 customers, who in turn supply to main dealers as tier 2, and so on. Other terms that are used to describe aspects of managing the supply chain are: