Everyday life bears a multitude of location problems and locational de- sions. These may be as simple as how best to place a pencil on a desk without having to reach too far and still keeping the work space clear, up to the question of where to place the next out of hundreds of thousands of transistors on a microchip. Some of these questions have easy answers, while others are so complex that not even satisfactory solutions are ava- able, never mind asking for optimized placement. The scales of problems reach from microchip design up to global trade and may demand consid- ation of one, two, three, or even more dimensions. As modern life encounters an ever increasing concentration in many - spects, usually a multitude of restrictions will be imposed on a problem. These restrictions maybe classifled as regions of limited or forbidden pla- ment of a new facility or as regions with limitations on traveling. Areas where the placement of a new facility is forbidden, referred to as forbidden regions, can be used to model, for example, protected areas or regions where the geographic characteristics forbid the construction of the desired facility. Limitations on traveling are constituted by barrier regions or obstacles like military regions, mountain ranges, lakes, big rivers, interstate highways, or, on smaller scales, machinery and conveyor belts in an industrial plant.