Abstract: Vendor Management Inventory(VMI)is a supply-chain initiative where the upriver enterprise is authorized to manage inventories of agreed-upon stock-keeping units at the downriver enterprises.This paper presents three models for coordinating inventory and delivery decision in VMI systems.These three models adopt time-based dispatch policy,quantity-based dispatch policy and time-and-quantity dispatch policy separately.The optimum parameters for each of these three models are given.Finally,advantages and disadvantages of these three policies are compared and applicable situations are analyzed.

Key words: Vendor Managed Inventory(VMI), supply-chain, dispatch policy