The OD Dock Yard Management System (DYM) is a leading-edge technology that keeps Old Dominion and our clients informed about the status of any freight or cargo shipment moving within the OD system at any given time. The Dock Yard Management System works by utilizing the bar code units located on each of our freight docks and in our switching tractors. When a shipment is loaded or unloaded, the status of the shipment is automatically uploaded and updated throughout the system.