Aplicação de programação linear baseada em geração de colunas ao corte de barras de aço destinadas à construção civil

Abstract

The construction companies need to improve their performance by implementing rationality improvements in their processes and management alternatives that led to operating cost reduction. Related to this, the aim was to study the One-Dimensional Cutting Stock Problem (1D-CSP), due to its application in the Civil Construction Industry with propositions to minimize raw material and labor costs, and waste reduction. The main challenge is to compare a linear programming model based on column generation applied to 1D-CSP in steel bars production that meets customer demand to the empirical method used by a company specialized in cutting and bending steel located in the city of Maracanaú/CE. For this purpose, a five-step research strategy was outlined, which was applied in the form of a case study to collect and analyze data from this company. The computational results demonstrated the efficiency of the column generation-based model for obtaining cutting patterns, the computational time required by the solver to return optimal solutions in the projects was 97.45 seconds on average. This represents a considerable gain from a practical point of view, as there is a decrease of more than 45,86% in the effort spent to plan the next cutting patterns to be performed at each requested stop. Regarding the productive capacity, the method predicted an average evolution of 11,03% and 3,98%, for bars with gauges of 12,50mm and 16,00mm, respectively. In monetary terms, annually, minimizing the use of bars in stock brings a reduction of R$ 314.658,46 and the waste reduction reaches the amount of R$ 334.594,39. The results obtained by the implemented model show considerable improvements in the defined objective, as the optimal solutions were found in a low computational time, it is believed that these approaches are promising to be applied in the industries of this segment. It is expected that the studied company analyze the results presented in this thesis as an initiative to restructure the planning methodologies and management stances with a focus on maintaining the competitive standard imposed by the market.