Combining Process Selection and lot sizing Models for Production Scheduling of Electrofused Grains

This work presents optimisation models to support decisions in the production planning and control of the electrofused grain industry. A case study was carried out in a Brazilian company with the aim of helping to increase productivity and improve customer service concerning meeting deadlines. Mixed integer linear programming models combining known models of process selection and single-stage lot sizing are applied for the production scheduling of electrofused grains. Optimising such scheduling is not a simple task mainly because of the scale of the equipment setup times, the diversity of the products and the limitations of the order due dates. A constructive heuristic is also proposed as an alternative solution method, particularly for large sized instances. The results show that the models, as well as the heuristic are capable of producing better solutions than the ones currently used by the company.