USING DYNAMIC-PROGRAMMING AND OVERLAPPING SUBPROBLEMS TO ADDRESS ADJACENCY IN LARGE HARVEST SCHEDULING PROBLEMS

The adjacency problem for forest management scheduling is formulated a s a dynamic programming problem. To overcome typical model-size proble ms, a solution strategy is proposed which links dynamic programming fo rmulations for overlapping subproblems. Subproblems are solved sequent ially in a moving-windows fashion. Solutions are near-optimal for thre e large but simplified test cases. Model size is sensitive to the size of the moving window. Using relatively small windows produced solutio ns that are closer to optimal than those found using two other modelin g approaches. Solutions are also insensitive to the side of the forest used to start the moving-windows process, and microcomputer solution times are not a major consideration, The strategy offers potential to treat adjacency measures as valued management outputs. It will likely fit well into broader forestwide models which decompose the forestwide problem into parts to help address other forestwide constraints.