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Summit - Sharing Resources |
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Load balancingINN-Reach software includes a feature that allows the consortium to influence which institution the system selects for initiating a Summit Borrowing request (when the item is available at more than one institution). This is sometimes called Load Balancing, or Request Balancing. In short, we assign numeric codes in priority order, so that whenever possible, the system selects the available item from the institution with the highest priority code, instead of using random selection. The intent is to help balance the load, intentionally directing requests to institutions that are heavy "net borrowers", and direct requests, whenever possible, away from those that are heavy "net lenders. An institution's priority code could also be changed temporarily to address unusual and extenuating circumstances. How it worksWhen an item is available for loan at more than one institution, the system will consult a table ("Request Balancing Table") containing a priority value for each institution. All institutions are assigned a code value, but more than one institution may have the same value. The system selects the institution with the highest numeric value. If two or more institutions have the same priority value, it randomly selects the lending institution from among them. (The table works similarly to the one used for record merging and matching.) The system does not automatically balance the lending load using a real-time analysis of lending statistics; it simply consults the table we provide. Where an item is owned by a single institution, there's no choice; that institution provides the material. We can't predict how much effect this feature will have overall, since the "overlap rate" (items owned by more than one institution) is about 25%, and we do not have information on how many loans involve titles with more than one owner. When the priority table is not used: When an item has been canceled with re-request (for example, first owning library can't find it, or it's too damaged to send out until repaired) the system does not consult the table to select another institution. According to III, it probably picks the first item available from the list of institution holdings. In 1998, staff canceled about 4.6% of all requests, and our procedures indicate that we use "with re-request" unless we are canceling on instruction from the patron. ImplementationStaff reviewed lending statistics and assigned priority codes accordingly, with approval of the Council. The new Lending Priority Codes were implemented on May 13, 1998. See following table. In late Fall of 1998, Staff reported the impact of implementing Load Balancing to Council. Alliance staff will examine net lending levels annually, averaged over the previous twelve months, and report to Council with recommended priority code changes when appropriate. For emergencies or any other situations that might suggest temporarily reassigning one or more code values, we will report to the Council Chair for direction. OngoingAlliance staff review Summit Borrowing statistics and make periodic adjustments as needed, continually working toward fair distribution of requests. During periods of extended closure, construction, etc., Alliance staff may make temporary adjustments to the load balancing table, or to item and/or patron circulation profiling. The Lending Priority Codeshighest number = highest priority, or first, for receiving the Patron Request, when more than one institution has an available itemlowest number = lowest priority, or last, for receiving Patron Request Center for Research Libraries (CRL) is always the lowest priority due to processing and transit time to fulfill patron requests. New members are placed near the bottom, as are libraries experiencing temporary problems filling requests in a timely manner (for example, due to construction projects or natural disasters). Alliance staff make minor adjustments to the table periodically, generally in the late summer and December holiday period, to keep the loan/borrow ratio as evenly balanced as possible. Where institutions have the same priority code, INN-Reach will select one randomly. When reviewing an institution’s priority, consider the priority code relative to other institutions (institutions above and below), not simply the priority number. In other words, an institution’s code may have changed to a greater number, for example, when table expanded from 21 to 28, but the number of institutions for the system to choose from before reaching it may have increased from 1 to 5, effectively lowering its priority ranking. For background: There are many factors that influence the Loan/Borrow ratio, and that will differ from one institution to another, such as: how much patrons use Summit Borrowing (frequency of requests per FTE), how many of the Owning Site’s items are eligible for requesting (by policy, status including whether items are checked out locally), and uniqueness of collection.Current priority Note: members move up or down from previous rankings, and trace places, moving above or below existing and new sites
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