Method and system for fulfilling requests in an inventory system

A system for storing inventory items, comprising:

• a plurality of holders operable to store objects;
• a plurality of inventory stations, wherein each of the plurality of inventory stations is associated with a queue comprising a plurality of queue spaces;
• and
• a management module operable to:
• receive a request indicating an activity to be completed;
• select, from a plurality of holders, a holder to fulfill the request;
• select, from a plurality of inventory stations, at least one inventory station at which to fulfill the request;
• instruct a mobile drive unit to move the selected holder from a first location to a second location remote from the selected inventory station;
• determine that a trigger event has occurred;
• and
• in response to determining that the trigger event has occurred, instruct the mobile drive unit to move the selected holder from the second location to a queue space of a queue associated with the selected inventory station.

A computer-program product stored on a computer-readable medium, the computer program comprising code operable, when executed, to:

• receive a request indicating an activity to be completed;
• select, from a plurality of holders, a holder to fulfill the request;
• select, from a plurality of inventory stations, at least one inventory station at which to fulfill the request, wherein each of the plurality of inventory stations is associated with a queue comprising a plurality of queue spaces;
• instruct a mobile drive unit to move the selected holder from a first location to a second location remote from the selected inventory station;
• determine that a trigger event has occurred;
• and
• in response to determining that the trigger event has occurred, instruct the mobile drive unit to move the selected holder from the second location to a queue space of a queue associated with the selected inventory station.

A system for retrieving inventory items within an inventory system, comprising:

• means for receiving a request indicating an activity to be completed;
• means for selecting, from a plurality of holders, a holder to fulfill the request;
• means for selecting, from a plurality of inventory stations, a least one inventory station at which to fulfill the request, wherein each of the plurality of inventory stations is associated with a queue comprising a plurality of queue spaces;
• means for moving the selected holder from a first location to a second location remote from the selected inventory station;
• means for determining that a trigger event has occurred;
• and
• means for in response to determining that the trigger event has occurred, moving the selected holder from the second location to a queue space of a queue associated with the selected inventory station.