AbstractThis paper describes a case study in which a simulation model, specifically an attraction-constrained spatial interaction model, is used to provide information to assist in the exploration of different options for the future provision of in-patient hospital facilities in an English Regional Health Authority. The model is used to evaluate options on the basis of their effect on two different criteria: first the level of utilization of hospital in-patient facilities relative to need of populations resident in different parts of the region, and secondly the relative ease of geographical access of the facilities to the populations served.