The aftermarket parts are built or remanufactured to replace damaged or worn OE parts, while the accessories are parts sold after the original sale of a vehicle intended to add to the comfort, convenience, performance, safety or customization of that vehicle.
OE parts, which account for an estimated two-thirds to three-fourths of total automotive parts production, may move via several routes on their way to the vehicle assembly plant, where they may be delivered in bulk or timed to arrive shortly prior to installation on the vehicle-known generally as Just-In-Time (JIT) delivery. These parts, components and systems destined for final assembly have three basic points of origin: Tier 1 suppliers that sell finished components and systems directly to the vehicle manufacturers;
Tier 2 suppliers that sell parts and materials for the finished components to the Tier 1 suppliers; and Tier 3 suppliers which supply raw materials. The Tier 3 companies may sell directly to the vehicle manufacturer, as well as to the Tier 1 and Tier 2 suppliers. Auto parts are shipped using both truck transports and railroads to move vehicles to dealerships, although air freight may be used if critical parts are needed as soon as possible in order to keep an assembly line moving. Offshore exports and imports are handled by ship. In addition to OE and OES parts, shipments also may include auto parts destined for the various national and regional parts distribution networks serving the aftermarket segments of the world.
OES parts, like automobile sales, have traditionally been handled through the franchised independent dealership networks in the major markets of the world. In the United States, the National Automobile Dealers Association (NADA) represents some 20,000 franchised new car and truck dealers holding nearly 43,000 separate franchises, both domestic and international (many dealerships represent multiple nameplates, including those from more than one manufacturer). In addition the American International Automobile Dealer Association (AIADA) represents 11,000 international nameplate automobile franchises.
The independent aftermarket distribution networks are much more complex. There are approximately 45,000 companies engaged in the wholesale and retail auto parts industry with combined revenues of $135 billion according to an industry overview by Hoover's, a business information resource firm. The aftermarket has traditionally consisted of wholesalers who purchase parts and components from the manufacturers; jobbers, intermediaries between wholesale distributors and retail operation; and the retail outlets.
A wholesaler typically buys from 200 to 300 vendors, including manufacturers who may also be producers of OE and OES parts, and from many of the thousands of smaller companies that make parts specifically for the aftermarket, according to Hoover's. A wholesalers' distribution center may carry 300,000 parts for virtually every conceivable vehicle on the road.
Retailers range from small, single-location operations to network operators such as Genuine Parts, AutoZone, Advance Auto Parts, CSK Auto, and Pep Boys. Hoover's reports that AutoZone has 3,200 stores and Genuine Parts fifty-eight distribution centers and 900 retail outlets. Some retailers sell to consumers, repair shops, and commercial installers-gas stations, fleet operators and car dealer service departments; some also operate their own repair departments.
