Heurísticas para um problema de dimensionamento de lotes com substituição de demanda e restrição de capacidade

Abstract

Lot sizing problems are important in the production planning and are challenged to determine a production plan that meets the demand of the product, respecting the available resources and minimizing costs. In this work we consider a lot sizing single-level problem with product substitution, ie, productive systems where a higher quality product or performance can meet the demand of one or more items using a conversion cost. We studied the reformulation by facility location proposed by Lang and Domschke (2010), with inclusion of overtime. As the problem is NP-hard, we propose heuristics based on the mathematical formulation of the problem: relax-and-fix and fix-and-optimize. Computational tests were performed based on instances Trigeiro et. al (1989) and Lang and Domschke (2010). Results and analysis are presented showing the efficiency of the methods.