Optimization of forest harvest scheduling at the operational level, considering precedence relationship among harvesting activities

The competitiveness of forest companies is strongly affected by the costs associated with getting the raw material to the mills. As harvesting costs contribute significantly to this cost, mathematical programming models were developed to optimize the scheduling of harvest activities within and between cut blocks to reduce the overall cost. However, the precedence relationship between harvesting activities occurring concurrently across multiple cut blocks has not been considered in the existing literature. In this paper, a mixed-integer linear programming model is developed to optimize the scheduling of harvesting activities, considering the precedence relationship among harvesting activities. The objective of the model is to minimize the total costs. The model determines the start time and end time of each harvesting activity at each cut block, considering the movement time of machines between cut blocks. The model is applied to the case of a large forest company in British Columbia, Canada. The model's harvesting cost is only 1.37% higher than the lowest possible harvesting cost, and only 3 assigned machines have an idle time. The detailed harvesting schedule is generated based on the start time, the end time, and the operating time for each activity at each cut block.

Automated summary

A mixed-integer linear programming model is developed in this paper to optimize the scheduling of harvesting activities, considering the precedence relationship among activities. The objective is to minimize the total costs by determining the start and end time of each activity at each cut block while considering machine movement time. The model is applied to a case study of a large forest company in British Columbia, Canada, with the result of a harvesting cost only 1.37% higher than the lowest possible cost and only 3 idle machines. A detailed harvesting schedule is generated based on the start and end time and operating time of each activity at each cut block.