The Weber problem in a multi-storey building

The multi-storey building is an architectural type whose structure contains ramps, stairs or lifts, which connect one floor to another. Population circulation inside the building involves the use of existing corridors on each floor and the lifts which connect adjacent floors. We study the location of a new facility in order to minimize the sum of distances to a set of demand points, sited in different floors of the building. To this end, a location-allocation model is formulated for the continuous and discrete versions of the problem. The solution of the problem is reached by applying a heuristic algorithm which alternates between location and allocation phases.