Addressed to both librarians and systems analysts, this book attempts to apply the analytic methods of operations research and systems analysis to the operating problems of the library. The first part of the book discusses theoretical models with emphasis on the pattern of book use, on its change with time and on the problem of estimating and evaluating the degree to which the library satisfies or fails to satisfy the seeker of information, and includes chapters on Library Use and Probability Distributions, Arrivals and the Poisson Distribution, Queues and Book Circulation Interference, and Book Use and the Markov Process. In the second part an actual sample library --the Science Library at M.I.T. -- is chosen to show how this theory can assist the managing librarian. An appendix gives tables of the Markov-Poisson Process. (RP)