An organization makes many models of cars, where a model is characterized by a name and a suffix (such as GL or XL which indicates the
degree of luxury) and an engine size. Each model is made up from many parts and each part may be used in the manufacture of more than one model.
Each part has a description and an id code. Each model of car is produced at just one of the firm's factories, which are located in Detroit, Los Angeles, Chicago and New York- one in each city. A factory produces many models of car and many types of part although each type of part is produced at one factory only.