Note on supply chain integration in vendor-managed inventory

In a recent paper Yao et al. present a single-buyer-single-supplier model to explore the effects of collaborative supply-chain initiatives such as vendor managed inventory (VMI). Several conclusions drawn from their model are arguable as (i) the model ignores the costs of shipments from the supplier to the buyer and (ii) the model times the incoming and outgoing flows at the supplier in a manner that overstates the inventory needed at the supplier.