Automated materials handling (AMH) refers to any automation that reduces or eliminates the need for humans to check-in, check-out, sort, or move totes or bins containing library material. The mechanical equipment used in AMH systems includes check-in  machines, sorters, conveyors, singulators, stackers and unstackers.Somewhere in the process there must be a scanner to read the bar code or a reader to read the RFID tag (or both.)  Various belts, pulleys, chutes, slides, and laser beams are used to ensure bins don't overflow and to get each item oriented correctly and pushed or carried into the right tote or bin. 

There is also a lot of software involved in every AMH system. The software is used to interact with the integrated library system (ILS) usually using the SIP2 protocol or some other API provided by the ILS. The ILS does its job of checking items in and out and the AMH software does the job of reading barcode numbers off the items and passing them along to the ILS. The AMH uses information it gets back from the ILS to sort each item according to a "sort plan." Sorting may be based on the status of the item, collection code, material type, shelving location or any combination of these pieces of information. The AMH system can also be configured to check-in the item, trigger a hold, print a holds slip, or send the item to an "exceptions bin" for special handling. The AMH system may also just read the information and make no changes to the item (e.g. no check-in and no triggering of holds, just sorting).

The typical library AMH system has one or more patron returns (e.g. one outside the library near the entrance, another one inside the library, and one available for drive-up) as well as an induction point for staff to use. Staff will induct material received via delivery or to handle the few items that are not inducted onto the system by patrons themselves. Each of these return and induction points receives material onto a convey which takes the material to the sorter.  Sorters are typically located in the circulation workroom but they can also be installed on the public side of the library.

The sorter is used to sort each item according to the sort plan that it is set to use.  Sorters may have more than one sort plan.  One sort plan might sort material to high-capacity bins after hours. Another sort plan might sort certain material to ready-to-shelve bins to speed up return-to-shelf time so the sort plan would be a little different than the after hours sort plan.  

Several vendors provide AMH systems. Generally, vendors that provide self-check-in machines also provide sorters and all the related machinery and software involved because the self-check-in machine is used to induct the material which then gets checked in and sorted.  These self-check-in systems with sorters eliminate several manual steps in the typical library materials handling workflow. 

Interlibrary Delivery (Branch) Sorters

Sorters with no direct connection to the patron check-in module are usually used for sorting interlibrary delivery items: material that has been requested from one library to fill a hold request at another library.In this scenario, the staff induct the material onto a sorter and items are sorted for each library in the system. The sort destinations are configured with interlibrary delivery totes. Even though these sorters are not located at the library (necessarily), they can save a lot of work for the workers at each library in the system who prepare outgoing delivery and who receive incoming delivery.

The ideal workflow that maximizes the interlibrary sorter is to use it to eliminate sorting and labeling at the outbound library and to eliminate item-level recieving at the receiving label. This requires coordination with the ILS vendor so that items that are being sent to fill a hold can have their Hold slip placed on or in the item at the sending library.  It also requires an AMH vendor that is capable of providing tote-level check-in for the receiving libraries. 

Dual Purpose Sorters

A sorter can service both the branch interlibrary delivery sort and operate as a library sorter with patron inductions. This is accomplished by switching between sort plans at different times of day.  Depending on the sort plan in use, the sort destinations may be configured with bins or ready-to-shelve carts (for sorting of patron returns) or with interlibrary delivery totes when sorting the interlibrary deliveries. Typically, all the items moving through the library system can be sorted in a couple hours so during that time, patron returns might just go to one bin for sorting later (although they'd still be checked in).