There is no suggestion that this can be viewed as self-contained. Closer inspection, however, reveals that there are many possible interactions. Any one of a large number of people may use the library. When doing so, that one person may interact with one or more documents, with one or more of many indexes, with library staff, with other users. The books are interrelated with each other and with the catalogs and indexes through common authorship, through being about the same sorts of things, through referring to each other directly and indirectly.
Libraries are generally small in organizational terms.
Libraries generally take up limited space and employ few people. An important property of systems is their ability to respond to changes, to adapt themselves to their environments, and to maintain sufficient stability to survive. The characteristics of library services in this regard seem contradictory. We shall return to this paradox in the final chapter. Controls and responses We have deliberately chosen to view library services, their users, and the interactions between them as a system.