Optimization of Ore Hauling in Open-Pit Mining

Ore haulage in open-pit mining is a critical stage of the production process, whose efficient scheduling has a direct impact on productivity and operating costs. The coordination of heterogeneous loading and hauling equipment, subject to capacity constraints, cycle times and multiple dumping points, gives rise to a combinatorial problem whose exact resolution is prohibitive for realistic instances. This work formulates it as a parallel machine scheduling problem with heterogeneous speeds and release times, and proposes five strategies to minimize the makespan: a mixed-integer programming model (MFOHOSM), two constructive heuristics (FIFO and SPT), an insertion-based local search (INSERT) and two tabu search metaheuristics (TSI and TSI-S). Evaluated on real instances from a ferronickel mine in Colombia, TSI achieves competitive GAPs at computation times two orders of magnitude below those of the exact model, positioning itself as a viable alternative for large-scale scenarios.