Short-term harvest planning including scheduling of harvest crews

摘要

The problem we consider is short-term harvesting planning for a total planning period of 4-6 weeks where we want to decide the harvest sequence or schedules for harvest crews. A schedule is an order or sequence of harvest areas assigned to each crew. The harvesting of areas is planned in order to meet industrial demand. The total cost includes harvesting, transportation, and storage. On considerable cost due to the quality reduction of logs stored at harvest areas. There are a number of restrictions to be considered. Areas are of varying size and the composition of assortments in each area is different. Each harvest team has different skills, a different home base, and different production capacity. Another aspect is the road network. There is a cost related to road opening (restoring, snow removal). In this paper, we develop a mixed integer programming (MIP) model for the problem. The schedules are represented by 0/1 variables. With a limited number of schedules, the problem can be solved by a commercial MIP solver. We have also developed a heuristic solution approach that provides high-quality integer solutions within a distinct time limit to be used when more schedules are used. Computational results from a major Swedish forest company are presented.