Location-Allocation Modeling

Some time ago, a real estate professional stated that there were three important issues in selecting a site for a business: location, location, and location. Although there are other important issues in business site selection, location is definitely one of the most important. Location modeling involves the development of a formal model and solution approach to identify the best place for an activity or a set of places for a set of related activities. Allocation is the related task of allocating services or activities provided by the facilities in order to meet geographically distributed demand. Locationallocation models optimize both location and allocation simultaneously.

There are many fundamental areas in which geographic information science (GISci) has advanced the field of location modeling and site selection. To discuss the role of GISci in location-allocation modeling, it is important to first define the difference between problems of location and problems of location-allocation. Then, we present a broad class of location-allocation modeling constructs that represent many different application areas. Finally, we describe how geographic information systems (GIS) are becoming an integral component in location modeling and how GISci is now joining operations research to provide some underlying scientific elements to the modeling process.