Patent ID: 7730046

Claim:
A method for locking a nomination item in a multi-user distribution scheduling system, comprising: concurrently presenting on a display of a computer system: a list of supply objects that model quantities of goods offered for sale by various sellers, supply object(s) to be included in a voyage; a list of demand objects that model quantities of goods desired for purchase by various buyers, demand object(s) to be included in the voyage; and a list of transportation objects that model delivery resources available from various transporters, transportation object(s) to be used for the voyage; responsive to user control, creating at least one nomination item associated with a voyage, the voyage including at least one supply object(s) selected from the list of supply objects, at least one demand object(s) selected from the list of demand objects and at least one transportation object(s) selected from the list of transportation objects; storing the nomination item in a database; modifying the nomination item by a first process; in response to the modifying, creating a lock object, associated with the nomination item, to prevent concurrent modifications by a second process of the nomination item and any one of the supply, demand and transportation data associated with the nomination item; requesting, by the second process, a save operation to be performed to save the modification to the nomination item made by the second process prior to a request to perform a save operation by the first process; in response to the requesting to save, determining whether a lock object has been created for the nomination item; if a lock object is determined to exist, preventing the storing of the modification made to the nomination item by the second process; storing the nomination item modified by the first process in the database; and deleting the lock object.