A combinatorial heuristic approach for solving real-size machinery location and road design problems in forestry planning

The location and operation of harvest machinery, along with the design and construction of access roads, are important problems faced by forestry planners, making up about 55% of total production costs. One of the main challenges consists of finding a design that will minimize the cost of installation and operation of harvest machinery, road construction, and timber transport, while complying with the technical restrictions that apply to the operation of harvesting equipment and road construction. We can model the network design problem as a mixed-integer linear programming problem. This model is fed with cartographic information, provided by a geographic information system (GIS), along with technical and economic parameters determined by the planner. We developed a specialized heuristic for the problem to obtain solutions that enable harvesting economically profitable volumes at a low cost. This methodology was programmed into a computer system known as PLANEX and is being applied in nine forestry companies that report important benefits from its use.