Abstract A DDA (Demand Driven Acquisitions) preferred Approval Plan allows libraries to acquire DDA eligible books triggered by users. Non-DDA books are acquired automatically, because there is no mechanism that allows these books to be requested by users. This study explores the procedure called Purchase by Request (PBR) that allows non-DDA books to be discoverable and requested by users. After incorporating both DDA and PBR into an Approval Plan, all books in the Approval Plan are exposed to users for just-in-time purchases, and in the process saving the library a substantial amount of money.

中文翻译：

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扩大需求驱动的收购：完整的及时批准计划

摘要 DDA（需求驱动的收购）首选审批计划允许图书馆获取由用户触发的符合 DDA 条件的图书。非 DDA 图书是自动获取的，因为没有允许用户请求这些图书的机制。本研究探讨了称为按请求购买 (PBR) 的过程，该过程允许用户发现和请求非 DDA 图书。在将 DDA 和 PBR 都纳入审批计划后，审批计划中的所有图书都向用户公开，以便及时购买，并在此过程中为图书馆节省了大量资金。