This paper proposes a sequential optimisation approach for addressing a complex real world problem of dispatch planning and freight loading for a set of highly irregular products with a heterogeneous fleet of trucks. The approach focuses on the case of goods with 'low-density values', highly varied with large travel distances. The proposed approach is based on a two-phase strategy: the first optimises the space assignment process inside trucks to each type of product. It is achieved by minimising long-haul transportation costs as a function of the fleet size and capacity, considering a set of predefined feasible and efficient loading solutions or patterns. The second phase minimises the number of visits per truck, assuming a fleet with fixed size and capacities for each type of product, which is determined in the first stage. The approach was successfully applied to a rolled steel company in Colombia, whose results show that the proposed model efficiently addresses the analysed problem, which is reflected in reasonable solution times and costs from a practical implementation perspective.
