A general global optimization approach for solving location problems in the plane

We propose a general approach for constructing bounds required for the "Big Triangle Small Triangle" (BTST) method for the solution of planar location problems. Optimization problems, which constitute a sum of individual functions, each a function of the Euclidean distance to a demand point, are analyzed and solved. These bounds are based on expressing each of the individual functions in the sum as a difference between two convex functions of the distance, which is not the same as convex functions of the location. Computational experiments with nine different location problems demonstrated the effectiveness of the proposed procedure.