Abstract: The server registers a plurality of supplier groups composed of one supplier or a combination of two or more suppliers so as to offer all items constituting a procurement object in a supplier group list. Then, it receives a bid price of a first supplier for an item included in the procurement object from a supplier terminal. Further, it selects the supplier group to which the first supplier belongs to with reference to the supplier group list and calculates a group bid price by summing up the bid prices of the suppliers belonging to the selected supplier group. Finally, it compares the calculated group bid price with the group bid prices of other supplier groups and determines a supplier group to be a candidate for the procurement object.