1. Vehicle-manufacturer procurement systems. The tiered relationship between vehicle manufacturers and component suppliers creates stable, long-term dependencies. It can therefore be difficult for a new entrant to replace an established approved supplier.

2. Quality certification, process audits and product approval. Suppliers must establish internationally recognized third-party quality systems specified by the manufacturer, such as ISO/TS 16949. Manufacturers also audit quality, cost, logistics, development and management, conduct on-site process reviews, and require each product to pass strict quality and long-duration vehicle tests.

3. Technology. Component manufacturers often develop distinctive production processes that improve performance, reliability and productivity while reducing cost. The original-equipment market also expects suppliers to develop new technologies and products and participate actively in simultaneous vehicle development.