A Linear Programming Optimization Model to Minimize Waste in Cutting Steel Rods for Table Manufacturing

This paper describes a linear programming optimization model to minimize the cutting waste in production of steel frames for school tables in a carpentry workshop. School tables are assembled from steel frames, wooden plates, and drawers. Most of the waste in manufacturing of tables was due to steel cutting operations. Round hollow steel pipes were cut into fixed dimensions for the table legs, in which case optimization was not necessary since only one dimension was cut from the same round pipes. However, for the steel frames, rectangular hollow pipes were cut into three different dimensions, which resulted in many different alternative cutting patterns. Because of the large number of alternative combinations of cutting patterns, it was necessary to optimize the process so that the waste was minimized. Linear programming model developed in this paper proved to be a valuable optimization tool in minimizing the waste by as much as 315 m of steel bars for each batch of production per month, which was directly reflected in savings.