A Method of Stock Roll Selection and Order Assignment by Analysis of Flaw Feature for A Rectangular Cutting Stock Problem Against Flawed and Selectable Stock Rolls

The target of this research is a rectangular cutting stock problem against flawed stock rolls, that orders are assigned to the stock rolls avoiding flaws and connecting the stock rolls for efficient assignment. The problem has the feature that total area of all stock rolls is larger than one of orders, so that, first the stock rolls used for assignment are selected from all stock rolls. In order to effectively use the “cumbersome stock rolls", whose assignment evaluation tends to be small, in this research, two methods are proposed; a method of formulizing degree of a cumbersome stock roll, and a method to connect divided stock rolls effectively. In the former method, the degree is expressed from two factors, namely rate of flaws' area and complexity of flaws, and the parameter is added to a total evaluation. In the latter, “improvement degree" of a pair of divided stock rolls is introduced, and the pair whose improvement degree is high, is connected. The proposed method has been applied to real cutting stock problems. It is confirmed that the method can generate the solutions as same level as expert's solutions.