Purpose -The purpose of this paper is to examine the advantages of developing a simulation model of the activities of a university library, in order to balance the available resources with demand for services. Meeting the demand is an essential part of managing a modern library. Inadequate levels of resources will result in excessive waiting times for the patrons. Design/methodology/approach -A simulation modeling approach is undertaken and the library activities of the University of Tennessee at Chattanooga (UTC) are simulated. Simulation modeling is an invaluable tool to understand the resource usage patterns and making intelligent budgeting choices. In the epoch of severe budget cuts, available financial resources must be carefully allocated where there is a critical need. Such a simulation modeling of the critical operations of an academic library of a campus upward of 11,000 students is presented in this study.Findings -A simulation model of the arrivals, flow, and usage patterns of library resources by the patrons described in this research, determined that there were four critical resources: the number of reference librarians, the number of checkout assistants, the number of computers, and the number of electronic gadgets. This study illustrates the need for careful analysis of arrival of patrons, resource levels, and resource usage with the objective of developing a resource level decision strategy that will result in an optimal level of resource usage by patrons. Practical implications -With the application of simulation models, it is possible to determine the needs for the limited resources at the library and coordinate the availability of the resources with the needs. Originality/value -Research in the use of simulation models for the determination of the resource levels that are best suited for an anticipated level of patron arrivals in the libraries is limited at best. This research adds value by providing information to fill this dearth of literature. The results of the simulation provided in this study can be used to develop budget priorities and to validate those priorities.