Implementation of health facilities in a new city

A new city is under construction in a developing country. The town will be organized in modules, and the population projection is established till the 90s. The ratio of medical personnel to inhabitants is fixed according to health policy criteria. The primary care system should be composed of a set of health centres which are identical with regard to equipment and personnel. The problem is to determine the number--and thus the size--of the health centres, and their location. The solution depends on two opposing factors: the total construction cost, which is increasing with the number of centres, and the walking distance for the patient, which is decreasing with the number of centres. For a given critical distance, we find--using techniques of location theory in network--the smallest number of centres that will ensure that all inhabitants are located within the critical distance. A Fortran program in which the sensitivity of the solution is studied as a function of the given critical distance is developed.