Optimization of sawing logs through integer linear programming
Name: HARLIANY DE BRITO MATIAS
Publication date: 20/02/2017
Advisor:
Name |
Role |
|---|---|
| ADRIANO RIBEIRO DE MENDONÇA | Co-advisor * |
| GILSON FERNANDES DA SILVA | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| ADRIANO RIBEIRO DE MENDONÇA | Co advisor * |
| GILSON FERNANDES DA SILVA | Advisor * |
Summary: The objective of this study was to develop a strategy to generate cutting alternatives for the wood log sawmill industry, using Integer Linear Programming. For this, a mathematical model was proposed that aims to functionally maximize the sawmill's revenue in the study, taking into account the raw material stock (logs), the Live Swaing and Cant Swaing cut patterns and the demand for the lumber products. For the study, the data were provided by Sawmill Santa Rita, located in Dores do Rio Preto, South in the Espírito Santo state. The stock data were 95 log length 2.5 m logs that were divided into six diameter classes (28, 30, 32, 34, 36 and 38), and the demand data were the products that the sawmill needed to saw to fulfill the request made by a client: P1 15x5 cm, P2 10x4 cm, P3 12,5x2,5 cm and P4 7x3 cm. A system was developed for simulation and optimization of the sawn sector, called here OptiSawn. The system consists of two modules. First, with the use of a recursive algorithm, all possible cutting planes are generated, after the generation of all possible cutting diagrams, the system writes the model based on Integer Linear Programming resolution method having as the resolution method the exact algorithm branch- And-cut. The Optisawn system generated a total of 84,668 cutting diagrams for the six diametric grades. Generating 84,160 for the Live Sawing cut pattern and 508 for the Cant Sawing standard. The Integer Linear Programming model resulted in revenues of R $ 4,193.43, indicating seven alternatives in the Live Sawing cutting pattern and three alternatives in the cutting pattern Cant Sawing.
Keywords: Cutting Diagrams; Mathematical Model; Yield in sawmills.
