This case study describes the application of an analytical library network model to data collected during April 1977. Models are developed for describing the intralibrary processing activities encountered at each of the resource libraries in the study, and alternative routing policies for referring requests among resource libraries are analyzed. A recommended routing policy is suggested which predicts an improvement in network probability of satisfaction and a slight decrease in writing time for roughly the same reimbursement cost experienced in April 1977. Understanding of the intralibrary processing activities is also useful for analyzing the impact of alternative technologies on network probability of satisfaction, processing time, and cost per request. Seven alternative technologies with various combinations of location and availability information are identified, and performance predictions for Illinois are estimated. Data tables are supplied; requests, tabulated by subject class and publication date, and recommended request routes for each system in the network are appended. (Author/JD)