Regular reviews were done of newer book detection systems with a view to replacing this system, including the latest in 1993, but there was never sufficient money to acquire a replacement. About 20 years ago, a decision was made to stop putting book plates in new books and journals and turn off the exit control system. That the old Checkpoint book detection and exit control system not be included in the planning for the new Info Lab. As stated above, the library staff having been doing annual inventories for many years. The results of about the last 10 years of inventories are included in Appendix B. During this period, when there was a deactivated security system, about 100-150 books a year were lost.
Some books missing in previous years return in any given inventory.
Because FIS has a research collection and has tried to be comprehensive, books in the LIS area are generally not withdrawn when they are missing even when staff have been unsuccessful in trying to replace them. Therefore, the total number of missing books slowly grows over time. In a collection of about 80,000 titles and about 400 books missing in the last inventory, the loss rate is still very low. Of course, this loss rate occurred during a period when, although the book detection system was deactivated, it was physically present. The psychological benefit of the physical presence of a book detection system should not be discounted.