Answer: Vendor-managed inventory (VMI)
Explanation: Vendor-managed inventory is the business system in which the product's vendor gain information about the product or service from the buyer or customer. Vendor takes the complete authority and managing of the list of products to make them present at location or area of utilization
The mentioned situation in the question is describing about vendor-managed inventory .The supplier directly supplies buyer's mentioned tools to the location of assembly line and also take the responsibility for it.