When library staff or patrons initiate a hold through the staff or public catalogue, Evergreen checks all related library settings, hold policies, and holdings under the title, to decide whether or not the hold can be placed.
If the hold can be placed Evergreen creates a hold request record which includes information such as patron, pickup library, request time, and notification method and contact details.
Evergreen also records the range of libraries' items that may be used to fill the hold in the hold record. This is recorded in the hold request record in a field called Selection Depth, which is viewable when viewing holds in either the patron’s account or the title record.
The value in for Selection Depth will either be 2 or 3. 3 means the hold will be filled by items belonging to the owning library or system. 2 means the hold can be filled by any holdable item within the library’s reciprocal borrowing zone.
Selection depth is not editable and Evergreen will not reassess the selection depth when the holdability of items change. To change the selection depth for a hold staff have to manually cancel then place the hold anew. A common situation where this may be needed if a library’s item has gone missing and they now want the hold to be filled by an interlibrary connect item.
When a hold is placed Evergreen creates an eligible item table which includes all eligible items that could potentially fill the hold. This table is not viewable within the staff client.
In the first 24 hours after a hold is placed, Evergreen looks for potential items to add to the eligible item table approximately every about 15 minutes. After the first 24 hours, Evergreen checks for eligible items once a day at approximately the time the hold was initially placed. The time is recorded in the hold request record in a field called Previous Check Time, which is viewable when viewing holds. If a potential target is found, it will be added to the hold target table. Items that are age hold protected will not be used to fill holds at other libraries.
While checking for eligible items to add to the table Evergreen is also retargeting the hold. It does this by removing the current target, checking the table, and picking another target, which may or may not be the originally targeted item.
When an item is checked in, Evergreen quickly goes through the eligible item table to see if the item can fill a hold and captures it if it can.
When an eligible item has the status of Available or Reshelving Evergreen will add it to the library’s pull list for hold requests. Though there may be multiple eligible items available, only one item may be put on the pull list at a time. If a different item is checked in first Evergreen will opportunistically capture the hold and the item will disappear from the pull list. Items will also disappear from the pull list as Evergreen retargets holds daily and assigns new hold targets.
When there are multiple eligible items available, Evergreen will first choose the pickup library’s copy, if available. Otherwise it will randomly pick up an item at another library, unless the pickup library imposes special rules prioritizing a preferred hold target source.
Newly catalogued items and items coming out of a non-holdable status (such as Lost) are not automatically added to the eligible item table. These items will be added when Evergreen does its daily check but libraries may prefer to force an earlier update of the table. This is done by retargeting the hold.
Holds are queued based on request time unless manually changed by library staff.
Separate holds queues are formed based on the potential target item range. For example, there is a hold queue for item level holds and another for title level holds. If a hold is targeting your library’s item for pick up at your library then other libraries' holds are not counted in the queue of holds.
Item level holds have a simple queue, which includes all holds targeting the item.
The title level holds queue counts all holds targeting any of the eligible items attached to that particular bibliographic record that the title hold may target, including the item level holds. You may notice missing queue numbers in item level holds queues; they are taken by the title level holds.
For libraries participating in reciprocal borrowing there will be separate queues based on the selection depth of the hold. Holds with a selection depth of 3 will have a separate queue based on the pickup library since they specially target the items owned by the pickup library. This means each library or system has its own queue if it has holdable copies.
Holds with a selection depth of 2 are queued together with the holds with a selection depth of 3 as items from any library in the zone including the pickup library can fill the hold. When looking at You may see missing queue numbers in selection depth 3 holds queues, which are taken by selection depth 2 holds.
To view holds with a selection depth of 3 for your library simply filter the holds by pickup library, where the pickup library is your library. The queue is arranged based on request time. As you view the queue you may notice that some queue numbers are missing. This means there hold with a selection depth of 2 that is filling that hold queue position.