Production planning with parallel lines and limited batch splitting: Mathematical model and a case study in the white goods sector

This paper addresses the optimization of production planning in the white goods sector, motivated by the real case of a home appliances manufacturer. The main characteristics of this productive process are multiple parallel assembly lines with distinct unrelated speeds that vary depending on product type; a tight limit on the maximum number of split batches; multiple product types that share different types of resources; and constraints on production capacity. For the company, it is important to consider all these characteristics in an integrated manner, which results in a complex decision-making process. To provide effective support to decision-making in this context, we propose an optimization model that seeks to meet the demand in the planning horizon considering all the mentioned characteristics, while minimizing the processing times and the number of split batches. The results of computational experiments with instances based on real data provided by the company showed that the proposed approach is effective and presents good quality solutions for the case study, suggesting significant productivity gains if put into practice. They indicate improvements in production times by up to 9.43% and reductions in batch splitting by approximately 55% with respect to the current operation of the company.