A system for reconciling a central inventory record having a count of products and location assignments for the instances of the count chooses instances for write-ons and write-offs based on the location assignments. When instances are to be written-on to the inventory record due to a shortage of instances in the record, then the added instances are assigned a location by detecting a shortage of instances for a particular location assignment relative to a proportionate amount and providing that location assignment to one or more of the added instances. When instances are to be written-off from the inventory record due to an excess number of instances in the record, the instances are removed by detecting excessive instances for a particular location assignment relative to a proportionate amount and removing one or more instances having that particular location assignment.