The Postal Service moves mail with a combination of Postal Service vehicles and contracted air, rail, truck, and ground services. Even though the daily volume of the mail can be estimated, there must be sufficient excess capacity to meet any variances and to meet service standards. This often results in available surplus capacity that can be utilized for inbound shipments of items purchased by the Postal Service. The item manager will analyze transportation requirements and work with Network Operations Management (NOM) to determine shipments that can potentially be moved on Postal freight. Asset Management will also be made aware of these opportunities so that they can provide backup support during high volume or other contingency periods. Property ownership normally transfers to the Postal Service when it is picked up; however, other arrangements can be established in the contract if there is a reason to have the supplier keep the risk.