Hi,

I need to understand the algorithm behind location allocation (MINIMIZE_FACILITIES). Does anyone know the details about that. The one on the GIS help website is not enough.

Basically, I need to know how GIS minimizes the number of the locations.

I suppose GIS first calculates (records) all feasible demand points a specific facility can cover within the cutoff time (this step can be done by service area). Then the GIS minimizes the total facilities number. So for the second step, does GIS use integer programming or some other ways to solve that?

Hope someone can provide some help.

Thanks a lot.

Li

I need to understand the algorithm behind location allocation (MINIMIZE_FACILITIES). Does anyone know the details about that. The one on the GIS help website is not enough.

Basically, I need to know how GIS minimizes the number of the locations.

I suppose GIS first calculates (records) all feasible demand points a specific facility can cover within the cutoff time (this step can be done by service area). Then the GIS minimizes the total facilities number. So for the second step, does GIS use integer programming or some other ways to solve that?

Hope someone can provide some help.

Thanks a lot.

Li

The ArcGIS Location-Allocation does not use any integer programming to solve this complicated combinatorial problem. It uses heuristics. The LP approach cannot be used to solve lvery arge problems and can take too long to converge to a good solution.

Details about the algorithm are listed here:

http://resources.arcgis.com/en/help/main/10.1/#/Algorithms_used_by_the_ArcGIS_Network_Analyst_extension/004700000053000000/

Jay Sandhu