A special case of serial production is worth noting. A baseline Inventory can be updated to current values by creating an Inventory SOP Instance with the incremental updates (new and changed Study records) that includes the baseline Inventory SOP Instance by reference. The IOD allows a Study to appear more than once in the tree of Inventory SOP Instances, and reconciliation of those records is facilitated by each appearance being tagged with its DateTime of extraction from the database. Note that if an updated Study is included in the incremental change inventory object, the full Study record as known at that time needs to be encoded (not just records for new or changed Series or Instances in the Study).

In this example, the Scope and Equipment for each object are the same, but the objects differ by their Content Date and Time. It is the responsibility of the creator to ensure that Study records in the incorporated Inventory object are either current as of the Content Date / Time, even though their time of extraction precedes that DateTime, or they are superseded by a current Study record in the incremental update inventory object.