The philosophy of user-driven collections is completely different than that which libraries have historically employed. This difference is typically described in the literature as just in time' versus 'just in case' collection development. In a time when it was slow and laborious to have library materials delivered, it made sense to have as much material stored on site, just in case someone wanted it, rather than having to wait for it to arrive after ordering. 'Just in time' was never soon enough. Libraries of all sizes (and their users) have lived by the just-in-case philosophy for many years. It is understandable that both library staff and users will feel alienated by a change in collection philosophy. This is the greatest barrier to implementing a user-drive collection model.'
Harris, Steven R.. "User-Driven Collections: Barriers to Implementation." (2013). https://digitalrepository.unm.edu/ulls_fsp/105