Suppliers that ship parts or materials directly to a manufacturer's production plants are called what?

• A. Tier 0 Suppliers
• B. Tier 1 Suppliers
• C. Tier 2 Suppliers
• D. Tier 3 Suppliers

Answer: (B)

Direct-supply relationships to a manufacturer's production plants are described as Tier 1. These are the suppliers that deliver parts or assemblies straight to the OEM’s production lines, enabling the actual manufacturing process to run smoothly. Tier 1 suppliers are the main link between the company and the rest of the supplier network, often coordinating with the OEM on design changes, quality standards, and delivery schedules.

Suppliers labeled Tier 2 or Tier 3 sit upstream in the chain, providing components and materials to Tier 1 rather than directly to the production plants. That means they support the Tier 1s, but their goods don’t go straight into the OEM’s manufacturing floor. In some frameworks, Tier 0 can refer to the OEM itself or the end-product entity, depending on the context, but the key point here is the direct delivery to the plant is characteristic of Tier 1. Understanding this helps with mapping risk and sustainability efforts, since disruptions or ESG performance at Tier 1 have immediate implications for production and downstream partners.