This paper proposes an approach to optimize the problem of integrated production lot sizing and sequencing in an animal feed plant. The problem consists of deciding how much of each feed to produce in each period, considering lot sequencing, so as to meet the demand while minimizing production and inventory costs. One of the major difficulties of production scheduling in this plant is to coordinate these decisions, since setup times are highly dependent on lot sequencing. The problem is modeled by mixed integer linear programming and is solved using the modeling language GAMS/CPLEX. Numerical experiments carried out with real data indicate that this approach can produce better results than those used by the plant.
production lot sizing; lot sequencing; sequence-dependent setup time; animal feed
