The variable" loan and duplication policy which was developed is described and also the considerable impact of implementation. The work is presented as a case study in library O.R. The great importance of analyzing the structure of problems is stressed and the nature and usefulness of models is described. (9 references) (Author/NH)

Proposes a model of library output as an abstract quantity, and relates it to other components of library performance. The consequences of basing library funding on such measurable outputs as circulation are also examined in light of the proposed model. A 13-item reference list and four figures are provided. (JL)

Mathematical models of library operations are presented which describe the amount of use made of resources by a user in a visit, the distribution of book circulation in a collection, the dependence of circulation on time, and the effect of multiple copies on user satisfaction. (9 references) (Author/NH)